DEPARTMENT OF THE INTERIOR

BULLETIN

OF THE

UNITED STATES

GEOLOGICAL SURVEY

3STo. 11

ON THE QUATERNARY AND RECENT MOLLUSCA OF THE 

GREAT BASIN, WITH DESCRIPTIONS OF NEW FORMS

WASHINGTON

GOVERNMENT PRINTING OFFICE

1884

ADVERTISEMENT.

[BoUetinNo.il.]

The publications of the United States Geological Survey are issued in accordance with the statute 

approved March 3,1879, which declares that 

'' The publications of the Geological Survey shall consist of the annual report of operations, geological 

and economic maps illustrating the resources and classifications of the lands, and reports upon general 

and economic geology and paleontology. The annual report of operations of the Geological Survey 

shall accompany the annual report of the Secretary of the Interior. All special memoirs and reports

of said Survey shall be issued in uniform quarto series if deemed necessary by the Director, but otherwise in ordinary octavos. Three thousand copies of each shall be published for scientific exchanges 

and for sale at the price of publication; and all literary and cartographic materials received in exchange 

shall be the property of the United States and form a part of the library of the organization: And the 

money resulting from the sale of such publications shall be covered into the Treasury of the United 

States." . On July 7,1882, the following joint resolution, referring to all Government publications, was passed 

by Congress:

" That whenever any document or report shall be ordered printed by Congress, there shall be printed 

in addition to the number in each case stated, the usual number [1,900] of copies for binding and 

distribution among those entitled to receive them."

Under these general laws it will be seen that none of the Survey publications are furnished to it for 

gratuitous distribution. The 3,000 copies of the Annual Report are distributed through the document' 

rooms of Congress. The 1,900 copies of each of the publications are distributed to the officers of the 

legislative and executive departments and to stated depositories throughout the United States.

Except, therefore, in those cases where an extra number of any publication is supplied to this office 

by special resolution of Congress, as has been done in the case of the Second, Third, Fourth, and Fifth 

Annual Reports, or where a number has been ordered for its use by the Secretary of the Interior, as in 

the case of "Williams's Mineral Resources, the Survey has no copies of any of its publications for gratuitous distribution.

ANNUAL REPORTS,

Of tbo Annual Reports there have been already published:

I. First Annual Report to the Hon. Carl Schurz, by Clarence^King. 1880. 8°. 79 pp. 1 map. A 

preliminary report describing plan of organization and publications.

II. Report of the Director of the United States Geological Survey for 1880-'81, by J. W. Powell. 

1882. 8°. Iv, 588pp. 61 pi. Imap.

IH. Third Annual Report of the United States Geological Survey, 1881-'82, by J. "W. Powell. 1883. 

8°. xviii, 564 pp. 67 pi. and maps.

IV. Fourth Annual Report of the United States Geological Survey, 1882-'83, by J. "W. PowelL 1884. 

8°. xii, 473 pp. 85 pi. and maps.

The Fifth Annual Report is in press.

MONOGRAPHS. ;i

So far as already determined upon, the list of the Monographs is as follows:

I. The Precious Metals, by Clarence King. In preparation.

II. Tertiary History of the Grand Caflon District, with atlas, by Capt C. E. Button. Published. 

HI. Geology of the Comstock Lode and Washoe District, with atlas, by George F. Becker. Published.

IV. Comstock Mining and Miners, by Eliot Lord. Published.

V. Copper-bearing Rocks of Lake Superior, by Prof. R. D. Irving. Published.

VI. Older Mesozoio Flora of Virginia, by Prof. Wm. M. Fontaine. Published.

VII. Silver-lead Deposits of Eureka, Nevada, by Joseph S. Cnrtis. Published. 

Vin. Paleontology of the Eureka District, Nevada, by Charles D. Walcott. In press. 

IX. Brachiopoda and Lamellibranchiata of the Green Marls and Clays of New Jersey, by R. P. 

"Whitfleld. In press.
ADVERTISEMENT.

g i

Geology and Mining Industry of Leadville, with atlas, by S. F. Emmons. In preparation. 

Geology of the Eureka Mining District, Nevada, with atlas, by Arnold Hayne. In preparation. 

Coal of the "United States, by Prof. R. Pumpelly. In preparation. 

Iron in the United States, by Prof. R. Pumpelly. In preparation. 

Lesser Metals and General Mining Resources, by Prof. R. Pumpelly. In preparation. 

Lake Bonneville, by G. K. Gilbert. In preparation.

Dinocerata. ' A Monograph on an extinct order of Ungulates, by Prof. 0. C. Marsh. In preparation. 

Sauropoda, by Prof. 0. C. Marsh. In preparation. 

Stegosanria, by Prof. 0. C. Marsh. In preparation.

Of these Monographs, Nos. II, HI, IV, V, VI, and VII are now published, viz: 

n. Tertiary History of the Grand Canon District, with atlas, by C. E. Button, Capt., U. S. A. 1882. 

4°. 264pp. 42 pL and atlas of 26 double sheets folio. Price $10.12.

III. Geology of the Comstock Lode and Washoe District, with atlas, by G. F. Becker. 1882. 4°. 

xv, 422 pp. 7 pi. and atlas of 2i sheets folio. Price $11.

IV. Comstock Mining and Miners, by Eliot Lord. 1883. 4°. xiv, 451 pp. 3 pi. Price $1.50.

V. Copper-bearing Rocks of Lake Superior, by Prof. R. D. Irving. 1883. 4°. xvi, 464 pp. 29 pi. 

Price $ .

VI. Contributions to the Knowledge of the Older Mesozoic Flora of Virginia, by "Win. M. Fontaine. 

1883. 4°. xix, 128 pp. 54 1. 54 pi. Price $ .

Vn. Silver-lead Deposits of Eureka, Nevada, by Joseph S. Curtis, 1884. 4°. xii, 200 pp. 15 pi. 

Price $ .

Nos. VHI and IX are in press and will soon appear. The others, to which numbers are not assigned, 

are in preparation.

BULLETINS.

The Bulletins of the Survey will contain such papers relating to the general purpose of its work as 

do not properly come under the heads of ANNUAL REPORTS or MONOGRAPHS.

Each of these Bulletins will contain but one paper and be complete in itself. They will, however, 

be numbered in a continuous series, and will in time be united into volumes of convenient size. To 

facilitate this each Bulletin will have two paginations, one proper to itself and one which belongs to 

it as part of the volume.

Of this series of Bulletins, Nos. 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are already published:

1. On Hypersthene-Andesite and on Triclinic Pyroxene in Augitic Rocks, by "Whitman Cross, with 

a Geological Sketch of Buffalo Peaks, Colorado, by S. F. Emmons. 1883. 8°. 42 pp. 2 pi. Price 10 cents.

2. Gold and Silver Conversion Tables, giving the coining value of Troy ounces of fine metal, &c., by 

Albert Williams, jr. 1883. 8°. ii, 8 pp. Price 5 cents.

3. On the Fossil Faunas of the Upper Devonian, along the meridian of 76° 30', from Tompkins.Connty, 

New York, to Bradford County, Pennsylvania, by Henry S. "Williams. 1884. 8°. 36pp. Price 5 cents.

4. On Mesozoic .Fossils, by Charles A. White. 1884. 8°. 36pp. 9 pi. Priee5cents

5. A Dictionary of Altitudes in the United States, compiled by Henry Gannett. 1884. 8°. 325pp.

Price 20 cents.

6. Elevations in the Dominion of Canada, by J. W. Spencer. 1884. 8°. 43pp. Price 5 cents.

7. Mapoteca Geologica Americana. .A catalogue of geological maps of America (North and South), 

1752-1881, by Jules Marcou and John Belknap Marcou. 1884. 8°. 184pp. Price 10 cents.

8. On Secondary Enlargements of Mineral Fragments in Certain Rocks, by R. D. Irving and C. R. 

Vanhise. 1884. 8°. 56 pp. Price 10 cents.

9. A Report of the Work Done in the Washington Laboratory during the fiscal year 1883-'84. F. W. 

Clarke, chief chemist; T. M. Chatard, assistant. 1884. 8°. 40pp. Price 5 cents.

10. On the Cambrian Faunas of North Am erica. Preliminary studies by Charles Doolittle Walcott. 

1884. 8°. 74pp. Price 5 cents.

11. On the Quaternary and Recent Mollusca of the Great Basin; with Descriptions of New Forms, by 

R. Ellsworth Call; introduced by a sketch of the Quaternary Lakes of the Great Basin, by G. K. 

Gilbert. 1884. 8°. 66pp. Price 5 cents.

STATISTICAL PAPERS.

A fourth series of publications having special reference to the mineral resources of the United States 

is contemplated. Of that series the first has been published, viz: Mineral Resources of the United 

States, by Albert Williams, jr. 1883. 8°. xvii, 813 pp. Price 50 cents.

Correspondence relating to the publications of the Survey, and all remittances, which must be by 

postal note 'or money order, should be addressed to the

DIRECTOR OF THE UNITED STATES GEOLOGICAL SURVEY,

Washington, D. 0 

WASHINGTON, D. C., August 30,1884.
DEPARTMENT OF THE INTEKIOK

BULLETIN

OF THE

UNITED STATES

GEOLOGICAL SURVEY

No. 11

WASHINGTON

GOVERNMENT PRINTING OFFICE

1884
IT. S. GEOLOGICAL SURVEY BULLETIN NO. 11 PL. I

IJSGENO

ifi, oflh& Columbia.

of the (cl<ara-(lo E333 

Offte

SKETCH MAP OF THE GREAT BASIN
UNITED STATES GEOLOGICAL SURVEY 

J. W. POWELL DIRECTOR

ON THE

QUATERNARY AND RECENT MOLLUSCA

OF THE

GREAT BASIN

WITH DESCRIPTIONS OF NEW FORMS

BY

K. ELLSWOBTH CALL

INTRODUCED BY A.

SKETCH OF THE QUATERNARY LAKES OF THE GREAT BASIN

G. K. QILBERT

WASHINGTON

GOVERNMENT PRINTING OFFICE

1884
CONTENTS.

Page.

INTRODUCTORY SKETCH OF THE QUATERNARY LAKES OF THE GREAT BASIN,

BYG. K. GILBERT....... ....................:.............................. 9

ON THE QUATERNARY AND EECENT MOLLUSCA OF THE GREAT BASIN, WITH DESCRIPTIONS OF NEW FORMS, BY R. ElLSWORTH CALL....................... 13

CHAPTER I. Systematic catalogue of the recent and Quaternary shells of the

Great Basin......................................................... 13

Introduction....^..................................................... 13

Catalogue ............................................................ 14

Lamellibranchiata.............................................. 14

Gasteropoda .................................................... 16

Ostracoda ...................................................... 23

CHAPTER II. Distribution and environment................................. 26

Geographic and chronologic distribution................ .............. 26

Depauperation versus salinity.......................................... 30

Depauperation versus temperature ..................................... 38

Hypsometric distribution.............................................. 41

Conclusions........................................................... 43

CHAPTER III. Descriptions of new forms ................................... 44

Valvatidae ............................................................ 44

Valvata sincera var. utahensis .................................... 44

Bissoidae...... .......................................................... 45

Amnicola dalli. .................................................. 45

Limnffiidse............ ................................................ 47

Eadix ampla var. utahensis ........... .......... ................ 47

Ltmnophysalonnevillcnsis... ...................................... 49

(359) 5

ILLUSTRATIONS.

PLATE I. Sketch map of the Great Basin................ . . .... 3

II. Comparative dimensions of Pomphotyx effusa ........................ 58

III. Comparative dimensions of shells............................ .. 60

IV. Comparative dimensions of shells from fresh and brackish stations. 62

V. Comparative dimensions of shells ................................. 64

VI. Ne-w recent and Quaternary mollusca ......... ....... ............. 66

FiG. 1. Diagram showing superposition of tufas ........................ .. 11

2. Dentition of Amnicola dalli.... ....................................... 46

3. Articulation of intermediate teeth ............................... 46

(361) 7

INTRODUCTORY SKETCH OF THE QUATERNARY 

LAKES OF THE GREAT BASIN. .

BY G. K. GILBERT.

The biologic investigation reported in this bulletin grew out of an inquiry into the physical history of the Great Basin during the Quaternary. It will be introduced by a brief account of that inquiry, with 

especial reference to a climatic problem which it was hoped the biologic 

investigation would aid in solving.

During at least a portion of the Quaternary the desert valleys of the 

Great Basin contained a system of lakes, in comparison with which the 

existing lakes of the same region are insignificant. These were incidentally studied by the geologists of the surveys directed by Mr. Clarence 

King, Capt. George M. Wheeler, and Maj. J. W. Powell, and the outlines of the largest lakes were approximately determined. The present 

Geological Survey has made them, the subject of an independent investigation, to the prosecution of which a corps of geologists was assigned.

The following facts have been ascertained: In the northern portion 

of the Great Basin there were two large water bodies j the one, Lake 

Bonneville, covering the Great Salt Lake and Sevier deserts, in western Utah; the other, Lake Lahontan, occupying a group of communicating valleys in western Nevada. Of smaller lakes, twenty-five have 

been explored, and it is probable that a still larger number remain to 

be examined. Previous to the epoch of Lake Bonneville its basin appears to have been arid, and the lake history was interrupted by an 

interval during which the water was greatly diminished, or may even 

have completely disappeared. There were, therefore, two floods, and 

corresponding to these there were two series of lacustrine deposits, 

separated by a zone of unconformity. The lower Bonneville beds are 

thicker than the upper, whence it is believed that the earlier flood was 

of longer duration than the later. There was a parallel series of events 

in the Lahontan Basin. The water rose and fell twice, and the beds 

deposited duriug the first rise form a thicker series than those deposited 

during the second.

This correspondence serves to confirm, and, indeed, practically to 

establish, the postulate early entertained that the fluctuations of these 

and other lakes of the region were not merely synchronous but were due 

to some general cause.

(363) 9
10 MOLLUSCA OF THE GREAT BASIN. [BULL. 11.

It has been further postulated that the general cause was climatic, 

and still further that it was identical with the cause of the glacial 

epoch, whatever that may have been. Such speculation of course implies the fact of a glacial epoch, and that fact is not universally admitted. / 

Nevertheless, the great majority of those who have studied the vestiges 

of ancient glaciers believe them to have been contemporaneous in different countries, and refer them to some cause of a very general nature.

It is held, moreover, by numerous glacialists that the epoch of ice 

extension was bipartite, the interval being characterized by conditions 

comparable with those which now exist; and if this view is well sustained, then the bipartite nature of the lacustrine histories goes far 

toward establishing the postulate which connects them with the glacial 

epoch.

With regard to the general nature of the glacial climate there is not 

a consensus of opinion. It is indeed held by the majority of investigators that the whole earth, or at least the zones including the glaciated 

areas, were then colder than now, but there is a considerable body of 

able geologists who maintain the contrary, arguing that an extension 

of glaciers is rather indicative of a general amelioration 'of climate. It 

is believed that the study of the lakes of the Great Basin should throw 

light upon this problem, and one of the ways in which it might be supposed to contribute to the subject is through a consideration of the 

faunas of the ancient lakes. If these indicate a lower temperature than 

now obtains, the view of the majority is to that extent sustained;. if 

they indicate a higher temperature the view of the minority is favored.

With these problems in mind, the fossil shells gathered from the 

Bonneville and .Lahoutan strata were placed in the hands of Mr. Call, 

and he was requested to compare them with existing forms, with a view 

to ascertaining whether their differeuceiS were susceptible of climatic interpretation. Finding the material too meager for the purpose, he afterward visited the region and spent several weeks in the collection of 

fossil and recent shells. How successful has been his quest, the reader 

may judge from the facts and inferences set forth in his report. Their 

discussion from d geologic point of view would here be out of place, 

but their application will soon be made by Mr. I. C. Russell and by the 

present writer, who have in preparation monographs 'on Lake Lahonton and Lake Bonneville.

Before closing, it is proper to explain two special elements of the 

lacustrine histories to which Mr. Call alludes in his.report.

The first of these is embodied in the terms "post-Bonueville," "postLahontau," and " semi-fossil." Besides the shells discovered living in 

existing waters and the shells entombed in the Quaternary strata, there 

are also great numbers which lie dead and bleached on the surface of 

the desert at considerable distances from streams or bodies of water. 

These shells doubtless lived in the ancient lakes after their desiccation 

had commenced, and before their areas had been so greatly diminished

(364)
GILBERT.] INTRODUCTORY SKETCH. 11

as we now find them. Presumably they .represent climatic conditions 

not greatly removed from those of modern times, but they nevertheless 

occur at stations which are now absolutely destitute of the conditions' 

essential to their growth. It is to shells of such occurrence that the 

above-quoted terms are applied.

The second special factor of the lacustrine history is embodied in the 

tufa deposits of the Lahontan area. These have been critically studied 

by Mr. Eussell, who recognizes three varieties superimposed in the man-.

_ Hijfkeek Stage of Second.

:::'':^-'V^^^^^

 :

 pYJfAMIJ) LAtfE

FIG. 1 Diagram showing superposition of tufas.

ner indicated by the diagram. The extreme height attained by the 

Lahontan waters during their first rise was 500 feet above the level of 

Pyramid Lake. Up to this height are found deposits of " lithoid " tufa. 

Over the li lithoid " tufa is deposited a distinct variety named " thinolite," but this reaches only one hundred feet above the surface of Pyra 

mid Lake. It rests unconformably upon eroded surfaces of the lithoid 

tufa, and is chronologically separated from it by an epoch during which 

the water fell to a lower plane than that marked by Pyramid Lake. 

The thinolite tufa therefore belpngs to the second Lahontan epoch and 

is synchronous with a portion of the Upper Lahontan beds. After its 

formation the water rose to its highest level, 530 feet above Pyramid 

Lake, or 30 feet higher than the first great rise. During this second high 

stage a third variety of tufa was deposited, the "dendritic," but it failed 

to attain the height of the lithoid. Its upper limit is 320 feet above 

Pyramid Lake. Up to the 100-foot contour it rests upon the thinolite* 

tufa. Higher up it is found in contact with lithoid tufa. Lake Lahontan had no outlet; and it is assumed that the salinity of its water varied 

with expansion and contraction just as that of Great Salt Lake is now 

known to vary. During the lithoid and dendritic epochs it was presumably a weaker solution than during the thinolite.

The reader who cares to inform himself more fully in regard to the 

history of these Quaternary lakes can do so by consulting the followingliterature:

U. S. Geographical Surveys West of the 100th Meridian. Vol. Ill,

(365)
12 MOLLUSC A OF THE GREAT BASIN. [BULL. 11.

Geology. Part I. Eeport upon the Geology of portions of Nevada, Utah, 

California, and Arizona, examined in the years 1871 and 1872. By G. 

K. Gilbert. Pp. 88-104. Part III. Geology of portions of Utah, Nevada, Arizona, and New Mexico, explored and surveyed in 1872 and 

1873. By E. E. Howell. Pp. 249-251.

U. S. Geological Exploration of the Fortieth Parallel. Vol. I. Systematic Geology. By Clarence King. Pp. 488-525.

U. S. Geological Survey. Second Annual Eeport. Contributions. to 

the History of Lake Bonneville. By G. K. Gilbert. Pp. 169-200.

U. S. Geological Survey. Third Annual Eeport. Sketch of the Geological History of Lake Lahontan; a Quaternary lake of northwestern 

Nevada. By Israel C. Eussell. Pp. 189-235.

U. S. Geological Survey. Fourth Annual Eeport. A Geological Eeconnaissance in Southern Oregon. By Israel 0. Eussell. Pp. 435-462.

(366)
ON THE QUATERNARY AND RECENT MOLLUSCA OF THE GREAT 

BASIN, WITH DESCRIPTIONS OF NEW FORMS.

BY E, ELLSWORTH CALL,

OHAPTEE I.

SYSTEMATIC CATALOGUE OF QUATERNARY AND RECENT 

SHELLS OF THE GREAT BASIN.

The material herein reported upon was derived in part from collections made by the Great Basin Division of the United States Geological Survey and in part from personal collections made under the auspices of the same organization. The material comes from numerous 

and widely separated localities, and is fairly representative of all the 

beds of ancient Lakes Lahontan and Bonneville. The first-named area 

furnishes the greater body of material, and also exhibits the more diverse fauna. /

The later beds present three identical forms in common Fluminicola 

fusca Hald., Helisoma trivolvis Say, and lAmnophysa palustris Miiller 

no one of which is characteristic of either area. These identical forms 

represent two distinct families of gasteropods, the first named belonging to the RissoidcB, the others to the Limnceidce. Each of these great 

families is represented by the characteristic species of each series of 

lacustrine beds, the Limnceidce being alone characteristically represented 

in the Lahontan beds, and the Rissoidw alone characteristically represented in the Bonneville beds.

The field treated in this paper is entirely new, and the methods 

adopted are also new. The results have been put into the form of 

tables of measurements, and these tables have been used as the basis 

of graphic representation.

The facies of the shells studied in a measure correspond with differences in size. That is to say, the weight, sculpture, and other taxonomic features were found to vary in almost or quite as marked a degree 

as the size.

(367) 13
14 MOLLUSCA OF THE GREAT BASIN. [BULL. 11.

The material upon which the included discussion is based is exhibited 

in the following catalogue 1 :

LAMELLIBRANCHIATA.

UNIONID.ZE. 

Genus MARQARITANA.'

Margaritana margaritifera Linn.

This species is circumpolar. It appears over a considerable area of 

the northeastern United States, Nova Scotia, New Brunswick, Newfoundland, and Quebec. Its western limit in this area is Central Pennsylvania. It reappears in the headwaters of the Missouri Eiver, and 

thence over all of the western United States, south to Arizona and 

north to British Columbia. It is somewhat common in streams near 

Salt Lake City, Utah, and occurs rarely at Elko, Nev., in the Hum- 

 fooldt Eiver. It is far smaller throughout its western range than are its 

eastern congeners. It has been found fossil at one locality only in the 

Lahontan area, in the Walker Eiver Canon, Nevada. Within the Bonneville area it is semi-fossil2 , or post-Bonneville, at numerous localities 

and notably in Sevier Desert.

Genus ANODONTA.

Anodonta nuttalliana Lea. Observations on Unto, Vol. II, 77 (1838). Transactions

Am. Phil. Soc., Vol. VI, PL 20, Fig. 62 (1838). 

Anodonta wahlametensis Lea. Trans. Am. Phil. Soc., Vol. VI, PI. 20, Fig. 64

(1838). Obs. on Unio, Vol. II, 78 (1838). 

Anodonta oregonensh Lea. Trans. Am. Phil. Soc., Vol. VI, PI. 21, Fig. 67 (1883).

Anodonta californimis Lea.Trans. Am, Phil, Soc,, Vol. X, PI. 25, Fig, 47, Obs.

on Unio, Vol. V, 42 (1852).

Vide also, Stearns, "On the History and Distribution of the Fresh Water 

Mussels and the Identity of certain alleged species." Proc. Gal. Acad. 

Sci., Nov. 20, (1882), p. 4 et seq. In this paper a vast array of facts is 

brought out, together with the necessary data to render the synonymy 

as here given absolutely certain.

The synonymy here indicated is based upon extensive suites from 

various localities on the Pacific slope and in the Great Basin. In its 

various forms the species has a wide distribution through California, 

Idaho, Oregon, Washington Territory, British Columbia, Vancouver's 

Island, Nevada, and Utah. Specimens were dredged in Utah Lake iii 

August, 1883. In the Lahontan area it is especially abundant in the 

Humboldt Eiver, and found sparingly in the Truckee Eiver, Nevada.

1 The bibliographic references given in connection with this catalogue are such 

only as are easily accessible; no attempt has been made to furnish a complete bibliography.

2 The special use of this term is explained on page 10, ante.

(368)
CALL.] LAMELLIBRANCHIATA. 15

It is found fossil in middle Lahontan beds at Mill City, Nev., and postLahontan beds on the desert east of Carson Lake. In the Bonneville 

area it has not yet been discovered in Bonneville beds, but abundant 

post-Bonneville fossils occur on Sevier Desert. It is somewhat common in fresh-water streams near Salt Lake City.

CURBICULID^}. 

Genus SPH^EEIUM.

Sphaerium striatiiium Lam.

Cyclas slriatina Lam. Animaux sans Vertebres, Vol. V, p. 560, (1818). 

Sphceritim striatinum Lain. Smithsonian Misc. Coll. No. 145, p. 37, Fig. 29 

(1865).

Widely distributed in the United States and Canada. Found fossil 

only at Eye Patch, Nev., in Upper Lahontan-beds.

Sphaerium dentatum Hald.

Cyclas dentatum Hald (Prime), Smithsonian Misc. Coll. No. 145, p. 40, Fig. 32 

(1865).

This species was originally described from Oregon, and has a somewhat limited distribution. In the Lahontan area it occurs in Humboldt 

Eiver, at Elko, and fossil in Upper Lahontan beds at Eye Patch, Nevada. It is a very abundant species in Utah Lake, where it attains a 

great size. Found as a post-Bonneville semi-fossil in great abundance 

upon the surface of Sevier Desert; occurs also in dredgings from Great 

Salt Lake, near the mouth of the Jordan Eiver, whence it was doubtless drifted or floated.

Genus PISIDIUM.

Fisidium ultramontanum Prime. Smithsonian Misc. Coll. No. 145, p. 75, Fig. 85 

(Appendix) (1865).

This species is rare and restricted in distribution. The original specimens came from California and Oregon. Found semi-fossil near Button's Eanch, Christmas Lakes, Oregon. As a fossil it occurs; (a) in 

estuary of highest Lahontan two miles southeast of Brown's, Nev.j 

(b) section on west side of Truckee Eiver, below Eeservation Bridge; 

and (G) in Upper Lahontan beds at Eye Patch, Nevada.

Fisidium compressum Prime. Proc. Bost. Soc. Nat. Hist., Vol. IV, 164 (1851). 

Smithsouian Misc. Coll. No. 145, p. 64, Fig. 67 (1865). ;

This species is very widely distributed, ranging from New England 

to California, and north into Canada. It is everywhere rare. In Lahontan beds it has been found at the base of the bone-beds on the 

south side of Walker Eiver Canon, Nevada, below the Narrows. It is 

there Lower Lahontan. Three specimens, living, were dredged in August, 1883, in Utah Lake.

(369)
16 MOLLUSC A OF THE GREAT BASIN. [BULL. H. .

Pisidium abditum Hal'd. Proc. Acad. Nat. Sci. Phil., Vol. I, p. 53 (1841). Smithsonian Misc. Coll. No. 145. p. 68, Fig. 72 (1865).

Twenty-seven different specific names are listed in the extensive 

synonymy credited, to this form by Prime in his monograph. Its distribution is so wide and the local conditions to which it is subjected are 

so various that its extensive synonymy is not remarkable. It has been 

found, living, in the Bonneville area, at only one locality City Creek, 

near Salt Lake City, Utah.

GASTEROPODA. 

LIMNjEHXSJ.

Genus HELISOMA. 

Heliaoma trivolvis Say.

PlanvrUstrivolvia Say. Nicholson's Encyc., PI. II, Fig. 2 (1817-18-19). Am.

Conch., Pt. VI, PI. LIV, Fig. 2 (1834). 

Heliaoma trivolvis Say. Smithsonian Miac. Coll. No. 143, pp. 115-121, Figs.

194-201 (1865).

This species is the most widely distributed form of the genus in North 

America, and is correspondingly variable. In the Lahontan area it is 

found fossil only at Eye Patch, Nev., in Upper Lahontan beds, and 

semi-fossil near Button's Ranch, Christmas Lake, Oregon. Living examples are very abundant at many localities, especially near Wadsworth, Nevada. In the Bonneville area it is less abundant, living. It 

has been found in Upper Bonneville beds, near Salt Spring Creek, and 

as a post-Bonneville fossil, on. the surface of the Sevier Desert.

Heliaoma ammon Gould. Proc. Bost. Soc. Nat. Hist., Vol. V, 129 (1855). Pacific 

Railroad Reports, Vol .V, 331, PL XI, Pigs. 12-18 (1857). Smithsonian

Misc. Coll. No. 143, p. 112, Fig. 187 (1865).

Eestricted in distribution to portions of California, Oregon, and Nevada. No specimens have been found in Lahontan beds, but it is 

abundant as a semi fossil on the surface of Humboldt Lake Basin near 

White Plains.

Genus GYRATJLUS.

Gyraulus parvus Say.

PlanorMs parvus Say. Nicholson's Encyc., PL I, Fig. 5 (1817, 1818, 1819). 

Gyraulus parvvs Say. Smithsonian Misc. Coll. No. 143, p. 139, Figs. 219-221 

(1865);

Generally distributed east of the Sierra. Found in Middle Lahontau 

beds at Mill City, and in Upper Lahontan beds at Eye Patch, Nevada. 

In the Bonneville Basin it has been found only at one locality living 

in a small pond at Fort Douglas, near Salt Lake City.

(370)
CALL.] UNIVALVES. 17

Gyraulus vermicularis Gould.

Planorlis vermicularis Gould. Proc. Bost. Soc. Nat. Hist., Vol. II, 212 (1847). 

Gyraulus vermicularis Gould. Smithsouian Misc. Coll. No. 134, 128, fig. 214 

(1865).

The distribution of this form is limited similarly with Hellsoma, ammon, namely, to portions of California, Nevada, and Oregon. The shells 

-submitted are from Button's Kanch, Christmas Lakes, Oregon, and are 

semi-fossil.

Genus MENETUS.

Menetus opercularis Gould.

PlanorUs opercularis Gould. Proc. Bost. Soc. Nat. Hist., Vol. II, p. 212 (1847). 

Menetus opercularis Gould. Smithsonian Misc. Coll. No. 143,125, Figs. 208-309 

(1865).

Distribution similar to the last, with the addition of Utah. In the 

Lahoutan area found (a) in Upper Laliontan lake beds, above tufa, Eye 

Patch, Nevada, and (&) in an estuary of the highest Lahontan beach, 

two miles southeast of Brown's, Nevada, of the same age. In the 

Bonneville area it is not found fossil, but is living in abundance in 

Warm Spring Lake, near Salt Lake City.

Genus LIMNJEA.

Limnsea stagnalis Linn.

This form, a true Limncea, is circumpolar in distribution, and ranges 

to high latitudes. It formed the subject of numerous experiments, alluded 

to below, made by Semper with reference to its powers of endurance of 

cold and other unusual conditions. Eare specimens were found semifossil in the Humboldt sink in the Lahontan area. It abounds, as a semifossil, in Sevier Desert, and numerous living examples occur near Salt 

Lake City, and in Utah Lake at American Fork, in the Bouneville Basin.

Genus LIMNOPHYSA.

Limnophysa palustris Mttller.

Helixpalustris Miiller. Teste Eackett, Trans. Linn. Soc., Vol. XIII, 42 (1822). 

Limnophysa palustris Mull. Smittisonian Miss. Coll. No. 143, p. 44, Figs. 60- 

66 (1865).

This form is circumboreal, and consequently exhibits many varieties. 

It is an abundant post-Lahontan fossil, and ranges downward to Upper Lahontan, in estuary of highest Lahontan beach, near Brown's, 

Nevada j and to Middle Lahontan in the medial stratified gravels of 

Mill City, Nevada. It is abundantly distributed, living and semi-fossil, 

throughout the Bonneville area, and is found fossil in Upper Bonneville beds, near Salt Spring Creek, Utah. It is very common and unusually large on the surface of Sevier Desert.

Limnophysa sumassi Baird. Proc. Zool. Soc. London, p. 68, 1863. Smithsonian 

Misc. Coll. No. 143, p. 43, Figs. 56-58 (1865).

The distribution of this form is restricted to the northwestern United 

States, and southwestern British America. It is doubtful whether it

(371) 

Bull. 11 2
18 MOLLUSC A OF THE GREAT BASIN. [BULL. n.

should be separated specifically from L. palustris Miill., with which it 

presents common taxonomic features. It is found fossil in Upper Lahontan beds at Brown's Station, Nevada. It is rare in the Bonneville 

area and fossil only at Matlin Pass, in Upper Bonneville beds, above 

the intermediate beach.

Limnophysa bulimoides Lea. Proc. Am. Phil. Soc., Vol. II, 33 (1841). Smithsonian 

Misc. Coll. No. 143, 61, Fig. 96 (1865).

This species is very restricted in distribution, being found only in parts 

of California, Nevada, Oregon, and Washington Territory, and doubtfully credited to Idaho. Found fossil in Alkali Valley, in sand just below Lahontan beds, and semi-fossil at Button's Ranch, Christmas Lakes, 

Oregon.

Limnophysa bonnevillensis Call.

The description of this form is given below. No living representatives are known. It occurs in Upper Bonneville beds, being abundant at 

Kelton, and common in Fish Spring Valley and near Willow Springs, 

Utah.

Limnophysa humilis Say. Jour. Acad. Nat. Sci. Phila., Vol. IT, 378 (1822). Smithsoniau Misc. Coll. No. 143, p. 63, Figs. 99-109 (1865).

This, another protean limnseid, to which numerous specific names have 

been applied, ranges through all the eastern United States and west to 

Nevada, though not yet discovered within the Bouueville Basin. It is 

found fossil in Upper Lahontan beds at Eye Patch, Nevada.

Genus PHYSA.

Physa gyrina Say. Jour. Acad. Nat. Sci. Phila., Vol. II, 171 (1821). Smithsonian 

Misc. Coll. No. 143, p. 77, Figs. 130-132 (1865).

Physa elliplica Lea. Trans. Am. Phil. Soc., Vol. v, 115, PI. XIX, Fig. S3 (1837).

This variety (?) of Physa heterostropha Say has not been found west 

of this area, where it is common. As a fossil it occurs only in Upper 

Bonneville beds, near Salt Spring Creek, Utah. The variety, to which 

Mr. Lea gave the name of elliptica, is found abundantly and of large size 

in Warm Spring Lake, near Salt Lake City. The rauge of the species 

is great, extending from this area eastward to Maine.

Physa heterostropha Say.

Limnoza hetwostropha Say. Nich. Encyc., PI. I, Fig. 6 (1817-1818-1819). 

Physa heterostropha Say. Smithsoniaii Misc. Coll. No. 143, Figs. 144-152 (1865).

This, one of the earliest described Physce of the United States, presents the greatest geographical range, and furnishes correspondingly 

numerous varieties. These varieties have been identified with the typical form to the number of thirteen, and there is evidence that a careful 

study will sensibly increase the synonymy. The species has not been 

found in the lake beds of either basin, but exists in some abundance 

as a semi-fossil on the surface of Sevier Desert.

(372)
CALL.] ' UNIVALVES. 19

Physa lordi, Baird. Proc. Zool. Soc. London, p. 68 (1863). Smithsonian Misc. Coll. 

No. 143, p. 76, Figs. 125-127 (1865).

This form is rare as a fossil, and has yet to be discovered living in the 

Bonneville Basin. A few examples have been found upon the surface 

of the Sevier Desert. The species is widely distributed in British 

America and in the northern United States, from Michigan westward.

Physa ampullacea Gould.

Physa lullata Gould. Proc. Boet. Soc. Nat. Hist., Vol. V, 128 (1855). Name

preoccupied and changed by author in lit. to Pliysa ampullacea. 

Physa ampullacea Gould. Sinlthsonian Misc. Coll. No. 143, p. 79, Figs. 134, 

135(1865).

While no specimens of this form are known in the Lahontan area, 

specimens have been used in the included discussion from contiguous 

localities in the Mono Basin, California. In the Bonneville area the 

species is a common one, living; this area also marks its most eastern 

known limit of distribution. 

Physa humerosa, Gould.

Proc. Bost. Soc. Nat. Hist., Vol. V, 128 (1855). Smithsonian Misc. Coll. No. 

143, 92, Fig. 157 (1865).

Colorado Desert, north to Pyramid Lake, in which it is living. Formerly abundant, judging from the thousands of semi-fossils on the surface of the desert. Known, living, only as above.

Genus KADIX.

Radix ampla var. utahensis Call.

A few specimens of this form were dredged in Utah Lake in August, 

1883, and are described herein. The superficial features would be 

perhaps insufficient to establish the variety, but the dentition 1 differs 

from typical R. ampla Mighels very materially. The specimens sustain 

to .B. ampla a similar relation to that exhibited by Pompliolyx costata 

Hemphill, a strongly marked variety of P. effusci Lea. The relation 

which it may genetically sustain to Polyrliytis Jcingii Meek, from the 

Tertiary of Cache Valley, Utah, is below indicated.

Genus POMPHOLYX.

Pompholyx effusa Lea. Proc. Acad. Nat. Sci. Phila., Vol. VIII, 80 (1856). Smithsonian Misc. Coll. No. 143, 74, Fig. 119 (1865). 

Pompholyx solida, Ball. Ann. Lye. Nat. Hist. N. Y., Vol. IX, 333-361, PI. II

(1870). 

Pompholyx costata, Hemphill. (Ms).

This species, with its varities P. costata Hemphill, from the Dalles, 

Oregon, and P. solida Dall, from White Pine, Nev., is the characteristic fjssil of the Lahontan beds, and is also highly characteristic in 

the modern fauna of that area. It is the only fossil found ranging from. 

Lower to Upper Lahontan strata, and occurs at many localities, often 

in the greatest abundance. It is one of the three forms now living in 

Pyramid Lake, but of a size far below that which it formerly attained. 

The principal variant features which it presents are below alluded to.

(373)
20 MOLLUSC A OF THE GREAT BASIN. ' [BULL. 11.

Genus CAEINIPEX.

Carinifex newberryi Lea.

Planorlis neidberryi Lea. Proc. Phila. Acad. Nat. Sci., 41 (1858). 

Carinifex neioberryi Lea. Smithsonian Misc. Coll. No. 143, 74, Figs. 120-122 

(1865). Also Steams, in Proc. Acad. Nat. Sci. Phila., 108-110, Figs. 25-27 

(1881).

In distribution this form is restricted to portions of California, Nevada, Utah, and Oregon. In the Lahontan Basin it ranges from the 

shores of Walker's Lake north to Button's Ranch, Christmas Lakes, 

Oregon, where it is found semi-fossil. Lahontan fossils have been 

found only at the south end of Winnemucca Lake, contiguous to Pyramid Lake. In the Bonneville area it was discovered living in Utah 

Lake. The specimens were rather small, and the peculiar flattening of 

the apical whorls made it an unusually interesting form. This is the 

most eastern locality yet reported. It is probably a comparatively recent addition to the fauna of the Bonneville Basin.

Genus ANCYLUS.

Ancylus newberryi Lea. Proc. Phila. Acad. Nat. Sci., 166 (1858). Smithsonian 

Misc. Coll. No. 143, p. 145, Fig. 244 (1865).

This shell is restricted in its distribution, so far as known, to California and Nevada. It has been found fossil only in Upper Lahontan 

beds in the white marl at the south end of Winnemucca Lake.

Ancylus, sp. undt.

A single specimen of this form was dredged in Utah Lake, in August, 

1883. No opportunity has been presented to complete the identification.

RISSOIDJS.

Genus AMNICOLA.

Amnicolalonginqua Gould. Proc. Bost. Soc. Nat. Hist., Vol. V, 130 (1855). Smithsonian Misc. Coll. No. 144, 87, Fig. 173 (1865).

Described by Dr. Gould from specimens collected during the progress 

of the Pacific Eailroad surveys on the Carson Desert. Until recently no 

living shells of the species were known; specimens which are referred 

to this species collected by H. Heinphill, near Lake Point, Utah, are in 

the Stearns Collection, Smithsonian Institution. It is found fossil in 

Upper Lahontan beds at south end of Winnemucca Lake, and at Buffalo 

Springs. Specimens appear to be rare in the Lahontan area.

Amnicola cincinnatiensia Anth.

Paludina cincinnatiensis Anth. Bost. Jour. Nat. Hist., Vol. Ill, pts. 1, 2, p.

279, PI. Ill, Fig. 3 (1840).

Amnicola cindnnatiensis Anth. List of Cincinnati shells (1843). Name 

changed, but no description.

See the next species.

(374) ,
CALL.] UNIVALVES. 21

Amnicola porata Say.

Paludina porata Say. Jour. Acad. Nat. Sci. Phila., Vol. II, 174 (1821). 

Amnicola porata Say. Smithsonian Misc. ColL No. 144, p. 82-83, Fig. 164 

(1865).

Both of these forms are abundant fossils in Upper Bonneville beds 

at various localities. The most abundant shell is the form referred 

to Amnicola cincinnaiiensis. Some hesitation has been experienced in 

adopting the specific name porata for the less common form. Neither 

species is known to be now living in the district included in the Bonneville drainage.

Amnicola dalli Call.

This form, described herein, is somewhat abundant living in a small 

stream tributary to Pyramid Lake, near the north end, at Syinon's 

Ranch. No fossil specimens of the species have been found.

Genus PYRGULA.

Pyrgula nevadensis Stearns. Proc. Phila. Acad. Nat. Sci., 173. Figure, (1883). 

Call & Beecher, in American Naturalist, September, 1884, Vol. XVIII, 

Pp. 851-855. In this paper the dentition is figured.

It is somewhat doubtful whether the generic reference of this form is 

correct. It appears to be devoid of the canal-like production of the aperture which is almost the sole generic character of Pyrgula. The only 

locality where living forms have been found is Pyramid Lake, Nevada, 

where it occurs in countless thousands. No examples are known from 

the Lahontan beds.

Genus FLUMINICOLA.

Fluminicola fusca Hald.

Leptoxis fusca Hald. Monograph of Leptoxis, 4, PI. Ill, IV, Figs. 83, 84 

(1847?).

The distribution of this genus is restricted, and especially is this true 

of the species here listed. It has been found only in portions of .California, Oregon, Nevada, Idaho, and Utah. It occurs fossil in both 

Upper Lahontan and Upper Bonueville beds, very abundantly in the 

latter at Kelton and Snowville, Utah, but sparingly in the Lahontan 

beds at Eye Patch, Nevada. Living forms are common in the Ogdeu 

River, and abundant in Utah Lake, Utah.

Genus VALVATA.

Valvata virens Tryon. Proc. Acad. Nat. Sci. Phila., 148, PI, I, Fig. 11 (1863). Smithsonian Misc. Coll. No. 144, p. 15, Fig. 21 (1865). ,

Restricted in distribution to Oregon, California, Nevada, and Utah. 

In the Lahontau area this shell occurs somewhat abundantly as an Upper Lahontan fossil. It is an abundant semi:fossil on the surface of 

Sevier Desert in the Bonneville area.

(375)
22 MOLLUSCA OF THE GREAT BASIN. [BULL. 11.

Valvata sincera var. utahensis Call.

This form is another of those found to be so distinct as to require 

mention as a variety. Its affinities are pointed out below. It is a very 

abundant shell at the north end of Utah Lake at Lehi.

PULMONATA GEOPHILA.

The collections of fossils made in the Bonneville area have not yet 

disclosed any land-shells, and but few have been found in the Lahontan 

basin. These represent but three genera and an equal number of species, none of which are abundant. They must be regarded as an adventitious fauna in the lake beds, washed down from higher land by 

rains and floods. As living shells they all range beyond the limits of 

the area.

In this catalogue reference is made only to those that have been 

found fossil, since our knowledge of the laud-shells of the Great Basin 

is much less complete than that pertaining to the fresh-water mollusca. 

All forms credited to either the Lahontan or the Bonneville area have, 

however, been listed in the accompanying synoptical tables.

HELICID^B. 

Genus VALLONTA.

Vallonia pulchella Mull.

Helix pulchella Mull. Vermes, p. 30. (Title and reference quoted.) 

Valloniaminuia Morse. Jour. Portland Soc., Nat. Hist.,Vol. I, 21, Figs. 54-56,

PI. VIII, Fig. 57.

Vallonia pulchella, MU11. Smithsonian Mis. Coll. No. 194 p. 157, Figs. 270-272 

(1869).

This is a circumboreal species, with wide southern distribution; it

also ranges to high altitudes. Fossil specimens have been found in 

Upper Lahontau beds at Eye Patch, Nevada.

Genus SUCCINEA.

Succinea stretchiana Bland. Annals N. Y. Lye. Nat. Hist., Vol. VIII, 168, Fig. 16 

(1865). Smithsouian Misc. Coll. No. 194, p. 263, Fig. 471 (1869).

Living specimens have been found only in Nevada. The fossil material comes from Upper Lahontan beds at Eye Patch, Nevada.

PUPID^B. 

Genus PDPILLA.

Pupilla muscorum Linn. Vide Pfeiffer, Mon. Hel. Viv. Vol. IV, p. -666. Smithsonian 

Misc. Coll. No. 194, p. 234, Figs. 397-401 (1869).

This is another circumboreal form, with wide southern range. Fossil 

only at Eye Patch, Nev., in Upper Lahontan beds.

(376)
CALL.] CRUSTACEA. 23

OSTRACODA.

Among the shells submitted for study occurred many thousands of a 

minute ostracoid crustacean, only the generic position of which has 

been made out as follows.

Genus CYPKIS.

Cypris sp. indt.

A. minute ostracoid crustacean is mentioned by White 3 as' very abundant west of Fairview and at the head of Soldier's Creek, Utah. While 

he does not positively identify it, he yet thinks it to be identical with 

Cypris leidyi E. & 8. The description of that species is not accessible 

at this time, and it is impossible to state whether the Lahontan forms 

are identical with the Utah form. Specimens occur abundantly in many 

localities in Lahontan Lake beds, and range from the surface of the 

highlands adjacent to the Truckee to and into the lithoid tufa at various 

points.

In the original description of Lake Bonueville4 the occurrence of 

" Cypris ?" is mentioned. The specimens are not at hand, but so far as 

information goes they agree in size and general appearance with those 

from Lahontau beds, and their specific identity is probable.

In tables 1 to IV following is given a synopsis of the recent and fossil 

shells discovered in the area studied.

TABLE I. Fossil Lahontan Mollusca.

Family.

Uiiionidaj. ...

ilissoidse..... 

Valvatidse . . .

(7)

Genus.

ilargaritana. . 

Anotionta ....

Pisidium .....

Gyraulus .....

Meuetus ...... 

Limnophysa . .

Aiunicola. .... 

Pyrgula ...... 

Flurainicola .. 

Valvata ......

Succinea......

(18)

Species.

margaritifera, Linn . 

nuttalliana, Lea .....

striatinum, Lam .... 

ultramoiitaiium, Prm 

eompressum, Prm ....

parvus, Say. .......... 

vermicularis, Gould .. 

opercularis, Gould.... 

palustris, Hiill .......

1.. ..............

longiuqua, Gould ..... 

nevadensia, Stearns... 

fusca. Hald ........... 

virens, Tryon .........

stretchiana, Bid ......

(26)

' Remarks.

North to British Columbia, east to Utah. 

To eastern limit of Great Basin.

Maine to Texas to California. 

Restricted. 

Rare.

Common. 

Oregon, California, Nevada.

Common, circumpolar.

Lake.

Only known as a fossil in the Lahontan area. 

Genus new to North America. 

Only one specimen found. 

Rare.

Nevada.

'United States Geol. and Geog. Sur. West of 100th. Meridian, Vol. IV, p. 216. 

«United States Geol. and Geog. Sur. West of the 100th Meridian, Vol. Ill, p. 99.

(377)
24 MOLLUSCA OF THE GREAT BASIN. 

TABLE II. Recent Mollusca of the Lahontan Area.

[BULL. 11.

Family.

Unionidse . . . . 

CorbiculidfB . 

Limnoeida; . . .

Rissoidse..... 

Helicidae.....

Pupidae .....

(6)

Genus.

Margaritana. . . 

Anodonta..... 

Sphserium .... 

Pisidium ..... 

Helisoina .....

Gyraulus .....

Menetus ..... 

Limnophysa . .

Physa ........

Pompholyx . . . 

Amnicola.....

Conulus ......

Succinea......

Pupilla ....... 

Leuchocheila .

(21)

Species.

margaritifera, Linn .....

compressum,' Prime. ....

parvus, Say ............. 

vorinicularis, Gould. ....

dalli, Call. ..............

ne'vadensis, Stearns.....

f ulvus, Drap ............

sillimani, Bland ......... 

Btretchiana, Bland ......

muscorum, Linn ........ 

corpulenta, Morse ......

. (39)

Remarks.

Huruboldt and Truckee Rivers. 

Abundant on surface of Carson Desert. 

Humboldt River. Abundant. 

Humboldt River. Common. 

Honey Lake. Walker and Quinn Rivers. 

Black Rock Desert. 

Common. Abundant at Wadsworth. 

Honey Lake, California. 

Ponds and small streams. 

Spring south end Pyramid Lake. 

Elko. Slougbs Humboldt River. 

Everywhere in ponds. Abundant. 

Honey Lake. 

Spring, south end Pyramid Lake. 

Black Rock Desert. Quinn River. 

Surface of desert. W h ite Plains. 

Common. 

Pyramid Lake. Carson Desert. 

Honey Lake. Mono Valley. 

Truckee River. Wadsworth. 

Pyramid Lake. 

Brook near north end Pyramid Lake. 

Pyramid Lake. Walker's Lake (living ?). 

Teste W. G. Blnney. 

Do. 

Do. 

Do. 

Do. 

Do. 

East slope Sierra Nevada. 

Var. costata. 

Sierra Nevada. Teste Binney. 

Humboldt Lake. 

Truckee Valley. Wadsworth. 

leste Binney. 

Do. 

Truckee Valley. Driftwood. 

Teste Binney. 

Do.

TABLE III. Fossil Bonneville Mollusca.

fP. B.=Post-Bonneville].

Family.

Limnseidai . . .

(6)

Genus.

Helisoma ..... 

Gyraulus .... 

Limnophyaa . .

(ID

Species.

trivolvis, Say ........... 

parvus, Say ............ 

palnstris, Mull..........

bonnevillensis, Call .....

cincinnatiensis, Anth . . .

en sis, Call.

(16)

Remarks.

Do.

Upper Bonneville. 

Semi-fossil. P.B. 

Upper Bonneville. 

Semi-fossil. P.B.

Upper Bonneville.

Semi-fossil. P. B.

Do.

Do.

Post-Bonneville.

 Do.

(378).
CALL.] SYNOPSIS. 

TABLE IV. Recent Mollusca of the Bonneville Basin;

'25

Family.

Unionid® .... 

Corbiculidao .

Limnaeida3 . . .

Valvatidae . . . 

Rissoidas..... 

Helicidoe.....

(6)

Genus.

Marganitana.. 

Anodonta..... 

Sphasrium ....

Pisidium .....

Helisoma ..... 

Gyraulus .....

Limnophysa . .

Carinifex .....

Bythinella .... 

Muminicola . .

Succiuea......

(22)

Species.

margaritifera, Linn ..... 

nuttalliana, Lea ........

compressum. Prime. . . . . 

trivolvis, Say ...........

ampla, Tar. utahensis, 

Call.

gyrina, Say .............

ampullacea, Gonld.. .....

smcera, var. utahensis. 

Call.

neata, Binney .........

34

Remarks.

Common throughout the basin. 

Do. 

Lake Utah. 

Sovier River. Streams. 

City Creek. 

Utah Lake. 

Numerous localities. 

Camp Douglas. 

Warm Spring Lake. 

Everywhere. 

Se%'ier River. 

Salt Lake City. 

Lehi. 

Warm Spring Lake. 

Utah' Lake. Warm Spring Lake. 

Lake Utah.

Warm Spring Lake. Var. P. gyrina,. 

Everywhere.

Numerous localities. 

Utah. Lake. 

Do. 

Do. 

Do.

City Creek. Spring Grouse Valley! 

Utah Lake. Ogden River. 

Wasatch Mts. 

Wasatch Mts. Ogden. 

Do. 

Salt Lake City. 

Dp. 

City Creek Canon. 

American Fork. 

Shores of Utah Lake. Lehi. 

City Creek Cafloii.

(379^
CHAPTEE II. 

DISTRIBUTION AND ENVIRONMENT.

GEOGRAPHIC AND CHRONOLOGIC DISTRIBUTION.

While there are certain facts of a physical character which justify the 

correlation in time of these lacustral beds, there exists no palseontologid 

evidence of that fact. The fossil mollusca are dissimilar, not only in 

their generic, but also in their family relations in many instances. The 

characteristic fossil of Lahontan Pompholyx effusa Lea is Iimna3id, 

while Amnicola porata Hald. and A. cincinnatiensis Anth., characteristic of the Bonneville beds, belong to the Rissoidce. The first family is inoperculate and pulmonate; the second operculate and pectinibranchiate. Eepresentatives of the genus Amnicola are now found 

common to both areas, but Pompholyx has not extended eastward into 

the Bonneville Basin, so far as known. But a kind of indirect evidence 

of correlation in time is furnished by increased abundance of fossil 

shells in those beds which are known to have been contemporaneous in 

origin with the highest level of each lake, and by their comparative 

paucity in those beds related to the lower stages. It is believed that 

this abundance or paucity may be correlated with the successive fluctuations of the lakes, and is dependent on them directly, or on the climatal conditions which caused them. If a valid argument can be based 

upon arbitrary estimates of the relative abundance of shells in turn 

based upon absolute abundance of fossils, then that abundance or paucity sustains a significant relation to humidity and to the tufa deposits 

in the case of Lake Lahoutaii. Thus, Pompholyx occurs sparingly in 

the lithoid tufa, is not found in thinolite at any point, becomes very 

abundant during the period of deposition of the dendritic tufa, and is 

found commonly but not abundantly in Pyramid Lake at the present 

time. These phenomena suggest a decided relation to humidity and to 

the varying chemical composition of the waters, which probably changed 

in nearly or quite the degree that humidity itself varied. Thus the 

history of Pompholyx in its relation to Lake Lahontan is most interesting but problematic. It is latterly associated with Pliysa humerosa 

Gould, and Pyrgula nevadensis Stearns, the only other mollusca now 

known to be living in that northern remnant of Lahontan Pyramid 

Lake. Pyrgula has replaced Pompholyx in the 'modern lake, and, indeed, is not known in any Lahontan deposit.

The only other locality where Pyrgula is known to occur is in Walker's 

Lake, but not now in the living state. Since careful collection has 

failed to reveal the form in Lahontan beds or Lahontan tufas, the hy26 (380)
CALL.] EELATIONS OF POMPHOLYX EFFUSA. 27

pothesis is justifiable that it has been introduced into each of these 

lakes since they became independent bodies. The genus is a new 

addition to the fauna of North America, is found in the mountainous 

districts of Europe, central Asia, and South America, aud has hitherto 

been known to exist only in pure fresh-water lakes and at considerable 

altitudes.5

The dentition of Pyrgula was unknown until its abundant collection 

in Pyramid Lake, when its description and illustration became possible.

The wide range of Pompholyx in Lahontan beds makes possible a 

valuable comparison of the same species from localities representing 

stages of the lake widely separated in point of time. Such comparisons 

as have been instituted show that its history alone will furnish an important addition to hexicology. Specimens taken from the lithoid tufa 

on Anaho Island, in Pyramid Lake, when compared with those from, 

horizons correlated with the dendritic period present the widest range 

among individuals. The shells from both localities are higher than 

Pyramid Lake forms, are much thinner, aud the coiling of the whorls 

is much looser. The lithoid tufa specimens present a large proportion 

of costate forms, the ratio being as 1 to 2, while in recent specimens the 

ratio is as 1 to 32. The recent specimens approximate P. effusa, var. 

ftolida Dall, while in sculpture and elevation the earlier and smooth 

forms of the lithoid tufa approach nearest to the typical P. effusa Lea.

The abundance of costate forms in the earlier beds, aud their comparative paucity among recent shells, is suggestive of genetic relation 

to. Voriicifcx binneyi Meek, of Miocene-Tertiary age, from Fossil Hill, 

Nevada. The existence of a very distinct carina on the body whorl of 

Pompholyx from Auaho Island, and its absence on recent forms, is still 

again suggestive of the same genetic relation. Lake Bonneville, in its 

Lake Utah representative, furnishes an allied fact. Radix ampla, var. 

utahensis] presents features allying it to Polyrhytis kingii Meek, from the 

Miocene-Tertiary of Cache Valley, Utah. Thus, in each of these great 

areas are recent forms of like family relations, but belonging to different genera, related respectively to forms nearly congeneric with them, 

but of Tertiary age. The differences which they present are certainly 

less specific than those exhibited in the Tertiary species of Planorbis 

from Steinheiin, which have recently formed the subject of an elaborate 

memoir.6

The comparative wealth in genera and species of the areas comprised 

in Lake Lahoutan and Bonneville, as well as the differences and identi-

 ' Pyrgula- scalariformis Wolf is an apparent exception to this statement, but ranch 

doubt attaches to the generic reference of the form so named. It was described from 

the post-Pliocene of Tazewell Co,, 111., in which a genus Pomatiopais sustaining a 

superficial resemblance to Pyryula is known to occur. Moreover, the correlation 

of species aud station, as above indicated, combined with the sole possible stations 

of the fossil forms, certifies the doubt.

6 Hyatt, "On the Tertiary Species of Planorbis at Steinheirn.". Aunivtrsary Me 

moirs Boston Society of Natural History, 1880.

(381)
28 MOLLUSCA OF THE GREAT BASIN. [BULL. 11.

ties of their fossil and recent mollusca, is succinctly shown in Table V,

following:

TABLE V. Distribution of Fresh-water Shells.

Family.

Rissoidse .......... 

Valvatidae .........

(5)

Genus.

Limnophysa ...... 

Limnsea ..........

Ph-uao

Ancylns .......... 

Anmicola. ........

Fluminicola ...... 

Pyrgnla ......... 

Bythinella. ....... 

Valvata. .........

(19)

Species.

stajinalis, Linn ..... ....... 

ampla, var. Utahensis, Call.

newberryi, Lea ............ 

dalli.Cail . ............

fusca, Hald ................. 

nevadensis, Stearns ........

sincera, var. utahensis, Call .

38

Lahontan.

Recent.

*

*

j

*

22

Fossil.

*

t*

* 

* 

*

t 

t

* 

* 

*

t* 

*

* 

t

t

t

t

1*

*

*

*

*18, t8

Bonneville.

Jecent.

*

* 

*

»

*

* 

* 

*

*

* 

*

*

*

*

*

22

Fossil.

t

t

it

t

t* 

t

t

t

1

.......

t*-

t

*6, tlO

NOTE. The asterisk (*) is used simply to indicate the presence of the species iii either the recent or 

the fossil fauna. The dagger (t) is used to indicate semi-fossils. When the same species is found 

both fossil and semi-fossil, the signs are -written together, with the relative abundance indicated by 

the order of the signs.

In this table only the fresh-water shells are listed. . But, comparing 

Tables I and III, in which land-forms are included, it will be observed 

that Lahontan furnishes eighteen genera and twenty-six species, comprised in seven families. Bonneville presents eleven genera and sixteen 

species, distributed among six families. Only^ix of the sixteen species 

are Bonneville fossils, but eight others are semi-fossils in the Booneville 

area. Of recent forms, as exhibited in Tables II and IY, the genera 

are equal in number, but are not all common to the two areas, and include all the known land-shells of the respective regions. Moreover, 

the Lahontan area furnishes an equal number of families and a greater 

number of species.

Of the thirty-eight species of freshwater shells, twenty-two are living 

in the Lahontan area, twenty-two in the Boniieville, and thirty in the 

entire district; twenty-three are known fossil or semi-fossil in the La-

(382)
'CALL.] DISTRIBUTION AND ENVIRONMENT. 29

hontan area, thirteen in the Bonneville, and twenty-eight in the entire 

district. The Lahontan area includes of living and fossil twenty-six, 

the Bonneville twenty-four.

It will at once be noted that the majority of 'fresh-water forms presented alike by all these five tables belong to the LimnceidcB. This 

family is world-wide in distribution, and exhibits a most remarkable 

group of genera and subgenera in its various divisions. Of all freshwater forms the species of Limnceidce have the greatest hypsometric 

range, extend to the highest latitudes, and best survive certain physical 

changes, sin-h as droughts, extremes of cold, and, as our investigations in 

the Great Basin prove, even transitions from fresh to saline waters. In 

the north temperate regions of America some species Limncea stagnalis, 

Bulimncea megasoma, Limnophysa palustris, L. sumassi, and Physa lordi 

 reach a high degree of perfection and appear to be eminently adapted 

to that habitat. Some of these Limncva stagnates and Limnophysa 

palustris are circuinboreal, and find in these latitudes their metropolis. The identity of other American with European forms is highly 

probable. Such species as are known to be common to Europe find 

their southernmost range in the Great Basin.

It is, perhaps, fortunate that this widely distributed family is so 

amply developed within this area. Its range is such that it here finds 

an almost infinite variety of station,7 often an environment structurally 

uncongenial, temperature ranges which may be either above or below 

its optimum, but which are comprised within wide limits, and, as might 

be expected, it presents a range of variation clearly co-ordinate with 

the physical conditions of its environment. Many of the variant features presented are clearly local or accidental j such, for example, as 

those which arise from distortion,8 traumatism, and so forth.

Eliminating these features, and those of kindred character and consequences, there yet remain other characters, such as size, color, thickness, and coiling of whorls, entirely dependent upon causes general in 

respect both to their range of operation and the effects they produce. 

Of these, one principal factor is food, in its character and abundance. 

So far as certain genera of Limnceidce furnish reliable data, their station 

is largely determined by food opportunities. In another great American family, not represented in the Great Basin the Strepomatidce the

7 " Station," as used herein, is to be understood as immediate and permanent physical 

environment; "habitat" is used in .the sense of geographic distribution.

8 Distortion is often clearly the result of purely ]ocal conditions, but even then varieties may be produced that present established features of a specific value in succeeding generations. The Steinheirn Planorles, previously cited, present a case in 

point. Ingersoll has described (in Annual Report of the Hayden Survey, 1874, p. 402, a 

distorted form of Helisoma (Planorbis) to which he gives the name H. plexata. The 

shells, which abounded in places where thrived a species of closely matted aquatic 

plant, came from a lake of considerable elevation (9,500 feet) in Antelope Park, Colorado. The shell was accommodating its growth to the ever-varying conditions of 

the pond in which it dwelt. In such a case as this the correlation of aberrant forms 

with their surroundings is comparatively an easy task.

(383)
30 MOLLUSCA OF THE GREAT BASIN. [BUT.L. 11.

same law holds true. They abound in the southern United States, in 

clear rocky mountain streams, in those stations suited to the growth of 

confervas, and their habitat is clearly connected therewith. The abundance of a species is, in a restricted sense, a measure of suitable food 

opportunities-; and the abundant shell fauna of the dendritic stage of 

Lahontan is a witness that fresh -water confervas the sole food of Pompliolyx flourished in great abundance. The wide range of variation 

seen in the vast numbers of that form from the Lahontan area, under 

conditions of abundance that lead to the elimination of food as a factor 

clearly point to some other potent agent, the effects of which are re 

remarkably uniform throughout the area.

DEPAUPERATION VCTSUS SALINITY.

Before passing to a consideration of these factors a further remark 

upon an anomaly in distribution as regards station is necessary. In 

both the Lahoutan and the Bonneville areas fresh-wab.-r species occur 

in brackish-water stations, accommodating themselves to abnormal conditions. In the Lahontan Basin the forms are found solely, as far as 

information goes, in lacustrine waters. Walker's Lake, quite fresh as 

compared with Pyramid Lake, has furnished no living shplls whatever; 

but Pyramid Lake, with ^^ of saline matter, abounds in the freshwater Pyrgula, and contains also Pompliolyx and Physa. ISTo bivalves 

of any kind have yet been found in either salt or brackish water. In 

the Bonneville area the forms occur in brackish springs, but in none of 

the salt or brackish lakes so far as known. Limnopliysa and Physa are 

the sole genera, each represented by a single species. The first of these 

genera has not yet been found in saline stations in the Lahontan area. 

On the other hand, neither Pomphotyx nor Pyrgula occurs in either fresh 

or salt waters in the Bonneville Basin. Physa alone is common to the 

fresh and saline stations of the two areas. When Pompholiees, of the 

Lahoutan area, from fresh-water stations, are compared with Pompholices from saline stations, the forms are seen to differ in some important 

particulars. Not only do the fresh-water Pompliolices grow to a much 

greater size, but they have thinner and lighter shells. The shape of 

the apertures presents a wider range of variation in the brackish-water 

forms, and the epidermis is lighter in color. It is believed that these 

differences have been successfully correlated with the differences of 

station saline or fresh water. In the Bonneville area the minimum of 

saline matter is found in the brackish springs, but the same biologic 

features, are presented.9 The shells of Physa and Limnophysa from

9 Some of these springs have a chemical constitution that varies "within wide limits 

at different times of the year. In the fall they are brackish, but in the spring fresh 

and sweet. See Stansbury's "Report on Expedition to Great Salt Lake," p. 174. 

Whether these are mollusk-bearing is unknown.

(384)
CALL.] DEPAUPERATION. 31

such stations are much less dense, the lines of growth are fainter and 

much closer, and the sculpturing is altogether more variable than in 

specimens derived from fresh-water streams adjacent.

That the power of accommodation possessed by these shells is not 

unlimited is sufficiently indicated by their uniform absence from salt 

marshes and from highly saturated saline lakes.

Tt is to be regretted that no data bearing on comparative salinity of 

springs and lakes in which mollusks have been taken living exists. 

They would surely have proven important aids in this discussion. The 

tables which follow are such as compare forms taken from fresh water 

with those known to come from stations of varying degree of salinity.30 

They are useful in establishing the obvious relation existing between 

the size of the various specimens and their environment. But, assuming that the various degrees of salinity presented by the springs,

from fresh-water to that of a percentage incompatible with the life of 

any limnseid, has been presented by Lake Lahontan since its beginning 

until now, the ratio of salinity has been and is a variable; as the lake 

levels rose and fell so did the variable decrease or increase in valueThis variable presumably found a biologic expression in the abundance 

of shell life, as has been above indicated in the case of Pompholyx, 

during the different tufa-forming periods of the lake. Table VI, based 

upon material from a fresh-water station and from Pyramid Lake, together with its graphic form in Plate II, Diagram I, shows this variable in living Pompholyx biologically expressed in difference of size.

TABLE VI. Pompholyx effusa Lea.

Number.

1.... .........................................

2.............................................

3.............................................

4.............................................

5.............................................

6.............................................

7.............................................

8

.

10.............................................

11............................................

Pyramid Lake.

Height.

mm. 

4.50 

4.44 

4.44 

4.50 

5.00 

5.78 

4.60 

5.22 

5.12 

5.40 

4.44

4.86-

Breadth.

mm. 

5.40 

5.20 

4.86 

5.00 

5.50 

6.00 

5. 50'

5.32 

5.20 

5.74 

5.50 '

5.38+

White Pine.

Height.

mm. 

5.60 

6.76 

7.00

6.45+

Breadth.

mm. 

c. fiO 

8.30 

8.40

7.76+

10 The discussion of this factor, salinity, is conspicuously incomplete. It could not 

.be rendered complete in the absence of salinity determinations for the various stations 

«laesed as " saline" and "brackish." The following list of salinites is pertinent but 

partial: Walker's Lake, Nevada, .9618 grams per liter, the average of two analyses 

by Prof. F. W. Clarke; Pyramid Lake, average of four analyses by Clarke, 2.2463 

grams per liter; Great Salt Lake (1868), 118.60 grams per liter (0. D. Alien); Little 

Gull Lake, in the Mono Valley, California, and Church Lake, near Salt Lake City, 

Utah, fresh. Pyi-amid and Walker's Lakes are herein classed as brackish. Salinity 

is used throughout this discussion, in the absence of an adequate specific term, in 

the sense of general chemical constitution. The determinations above given include 

only sodium chloride.

(385)
32 MOLLUSCA OF THE GREAT BASIN. [BULL. 11.

The value of this table would, probably, have been enhanced by a 

greater number of specimens from the White Pine locality, but, as usually happens, unless the collector use especial care, only the largest and 

most easily discoverable forms appear, and these were adults. The 

ratio of heights of the White Pine specimens to tae same dimension of 

Pyramid Lake specimens is "D, and for breadth ^, a result clearly connected with station. Both localities present that form known as Pomphohjac effusa, var. solida Dall, but not differing in well-marked particulars from the typical P. effusa Lea.

In Table VJI are presented a series of measurements of this same 

species from localities which have been correlated with three different 

stages of water in Lahontan, in each of which the ratio of salinity differed. Plate II, Diagram II, is based upon this table. During the 

period of the deposition of the beds at White Terrace the most noticeable 

effect of environment is expressed in a height of shell which is certainly 

anomalous. Joined to this, as its consequent, is a far greater convexity 

of whorl than is shown by any specimens from beds deposited before or

since.

TABLE VII. Pompholyx effusa Lea.

Number.

1.................... ...................

2........................................

3........................................

4...... .................................

5........................................

C...........1...... ......................

7........................................

8........................................

9 .......................................

ID.......................................

11.......................................

13

14.......................................

IP;

16 ......................................

17.......................................

18.......................................

19.......................................

20.......................................

91

22.......................................

9T

24................................... ..

25............ ..........................

Anaho Island.

Height.

mm. 

4.20 

3.50 

3.96 

3.76 

4.62 

3. 68 

3.28 

4.24 

3.50 

2.88

3.76-JBreadth.

mm. 

5.20 

4.44 

5.16 

4.36 

6.16 

4.86 

4.92 

5.44 

5.50 

4.30

5.23+

White Terrace.

Height.

mm. 

8.08 

8.10 

7.40 

6.64 

. 8.90 

6.80 

8.50 

7.36 

6.86 

7.32 

7.00 

5.50 

6.50

7.30

Breadth.

mm. 

5.00 

6.40 

5.50 

5.00 

5.50 

4.86 

5.28 

5.40 

5.00 

5.00 

5.10 

4.42 

4.50

5.15

Pyramid Lake.

Height,

mm. 

4.10 

5.86 

6.36 

5.50 

5.36 

6.50 

5.88 

7.36 

5.98 

5.68 

5.70 

5.26 

5.60 

7.70 

5.22 

5 34

5.28 

5.12 

4.10 

5.48 

5.00 

4.88 

5.14 

5.30 

6.00

5.43-

Breadth.

mm. 

5.32 

6.28 

5.84 

7.04 

6.66 

7.40 

6.60 

6.10 

7.10 

6.62 

6.98 

5.82 

6.80 

3.36 

6.32 

6.42 

6.72 

6.04 

5.56 

6.G6 

6.30 

5.82 

6.16 

6.18 

7.04

' C.28+

Evidence of a similar character is presented by Table VIII, graph 

ically represented in Plate III, Diagram I. The measurements in this 

instance are based upon specimens of Carinifex from two localities, the 

deposits of which, though derived from different lakes, were both late 

Quaternary and may have been contemporaneous. Those from the 

south end of Winnemucca Lake are from beds deposited at approximately the same date as the lake beds at White Terrace, the locality 

used in the construction of Table VII. Those from Christinas Lake

(386)
CALL.] MEASUREMENTS OF SHELLS. 33

were found on the surface of a plain in company with the bones of extinct mammals. The ratio of size for the Winnemucca fossils, as compared with the Oregon shells, is, for height 'H, and for breadth jpf.

TABLE VIII. Carinifex newberryi Lea.

Number.

1.. ............................................................

.2.............................................................

3.............................................................

4.............................................................

5.............................................................

 8.............................................................

7.............................................................

is.............................................................

 n

Winnemncca Lake 

(fossil).

Height.

mm. 

8.54 

11. 50 

11.28 

10.10 

11.22 

10.18 

9.00

10.26

Breadth.

mm. 

10. 50 

11.68 

11.78 

13.10 

12.70 

11.74 

9.50

11.58

Christmas Lake.

Height,

mm. 

8.53 

8.00 

7.50 

9.50 

9.00 

10.30 

9.30 

8.50 

8.50

8.79+

Breadth.

mm. 

10.20 

10.48 

9.32 

10.10 

11. 00 

10.10 

9.30 

10.52 

9.24

10.03

In the JBonneville Basin similar results are exhibited by the measurements of shells obtained from, brackish springs. In some cases comparisons have been instituted between shells collected in contiguous areas, 

thus insuring equal climatal conditions, but in other cases between 

shells from regions more remote. Thus in Table IX, upon which is 

based Plate III, Diagram II, specimens found fossil, lying upon the 

surface of the desert east of south Carson Lake, Nevada, are compared 

with specimens of the same species from Warm Spring Lake, Utah. 

The ratio of size is nearly as 1 to 2; but, as will appear below, the Utah 

specimens were specially favored by another factor, of climatal nature. 

The smallest of the Warm Spring Lake specimens is far above the 

largest of the Carson Desert forms.

TABLE IX. Helisoma trivolvis Say.

* Number.

1. ............................................................

4.............................................................

6....................................- ....................

7............................................................

8............................................................

9

10............................................................

11............................................................

12............................................................

14............................................................

15............................................................

16............................................................

17............................................................

18............................................................

19............................................................

20............................................................

21.......:....................................................

22............................................................

Carson Lake Desert.

Height,

mm. 

7.00 

6.90 

 8.24 

7.32 

6.50 

6.84 

7.50 

6.56 

5.90 

5.«8 

6.10 

6.20

6.74-f

Breadth.

mm. 

13.00 

12. 20 

15.58 

11.64 

7.12 

14.60 

9.60 

12.86 

11.00 

9.60 

11.00 

11.70

11. 66-

Wann Spring Lake.

Height.

mm. 

11.00 

10.80 

11. 30 

11.00 

10. 44 

10.82 

10.64 

11.24 

10.32 

11.54 

12.38 

11.50 

10.88 

10.74 

10.50 

10.16 

10. 94 

11.50 

11.08 

10.26 

11.06 

11.96

11. 00+

Breadth.

mm. 

21.10 

19.80 

25.10 

20.26 

21.84 

20.00 

19.00 

21.12 

22.08 

19.80 

25.38 

25.76 

17.60 

22.00 

25.50 

19.64 

21.60 - 

22.20 

23.10 

21.42 

24.00 

25.90

21.87-f

Bull. M 3 (387)
34 MOLLUSCA OF THE GREAT BASIN. IBULL. 11.

No lakes of the Bonneville area, except those entirely fresh, are 

known to be mollusk-bearing. Moreover, there have been fouod no 

fossil shells ranging in point of time, throughout the Bonneville beds 

upon \vhich to base any conclusion, as in the case of Lahoutan, concerning the effect of any degree of salinity upon them, if they existed. But 

a similar line of corroborative evidence is presented by the shells from 

brackish springs. Upon such material have been based Tables X and 

XI, and Plate IV, Diagrams I and II. Here again, in the case of Warm 

Spring Lake-, the climatal factor is brought out prominently. In these 

tables are exhibited similar results, seen by comparing the averages 

in the case of two new genera not known in the saline waters of the 

Lahontan area, but subjected to environmental conditions similar to 

those of Pompholyx. The physiologic effects of the similar stations are

identical.

.r Limnophyaa palu&tria MU11.

Number.

1...... .....................

2...........................

3...........................

4...........................

5...........................

6...........................

7...........................

A

10...........................

11...........................

12...........................

13...........................

14..................... .....

15...........................

16...........................

17...........................

18...........................

1Q

20 ..........................

21...........................

22...........................

23...........................

24...........................

25...........................

Honey Lake.

Length.

m. m. 

29.50 

28.20 

- 24. 80 

' 23.16 

26.50 

25.70 

25.20 

25.12 

24.50 

30.40 

19.70 

23.20 

26.00 

17.80 

1.7. 00 21.00 ' 

19.50 

20.50

23.28+

Breadth.

m. m. 

9.90 

9.50 

9.80 

9.80 

11.20 

10.22 

10.90 

9.90 

9.80 

11.50 

8.70 

10.00 

9.60 

7.12 

7.50 

8.30 

7.10 

8.52

9.38+

Warm Spa Lake.

Length.

m. m. 

18.50 

23.04 

24.08 

19.00 

27.16 

26.50 

25.20 

26.80 

29.00 

28.04 

28.48 

23.38 . 27.00 

24.50 

26.50 

20.40 

25.70 

23.70 

29.24 

25.70 

26.10 

27.52 

29.42 

29.88 

33.10

' 25. 82+

Breadth.

m,. m. 

7.32 

9.14 

10.06 

9.54 

11.64 

11.58 

11.60 

11. 32 

11.70 

, 12. 16 

12.40 

9.64 

11.92 

10.48 

11.40 

8.24 

11.30 

10.06 

. 12. 24 

9.44 

10.56 

11.70 

11.50 

12.04 

13.50

10. 92+

Brackish Springs (Promontory).

Length.

m. m. 

16.50 

25.46 

19.00 

22.12 

21.10 

18.90 

22.36 

26.10 

16.80 

14.34 

16.86 

16.34 

15. 50 

19.06 

19.00 

22.30 

22.24 

15.60 

18.78 

16.32 

21.44 

19.28 

21.88 

25.62

19.40+

Breadth. 

m. m. 

7.30 

10.74 

7.72 

9.50 

8.40 

8.70 

8.80 

10.12 

7.60 

6.94 

7.08 

7.42 

6.70 

9.00 

8.20 

8.92 

9.20 

6.68 

8.04 

8.72 

10.00 

9. 22 

9.50 

10.90

8.50+

TABLE ~Kl. Phy8a gyrina Say.

Number. 

/

\...............^............... ..............................

4... ...................................................... ...

5............................................................

6............................................................

7........ .............................................. ....

Salt Lake City 

(ponds).

Length.

mm. 

18.96 

20.32 

19.00 

19.24 

16.50 

16.34 

18.50

Breadth.

mm. 

9.86 

11.58 

10.42 

10.50 

9.12 

9.70 

10.50

Promontory (Brackish Springs).

Length.

mm. 

13.30 

14.24 

15.00 

14.32 

17.60 

16.12 

16.00

Breadth.

mm. 

6.30 

7.48 

0.88 

6.74 

8.52 

7.70 

7.64

(388)
SUMMARY OF RESULTS. 

TABLE XI. Physa gyrina Say Continued.

35

Number. 

/

8...... .....................................................

9............. ...............................................

10............................................................

11...........................................................

12................... ........................................

13............................................................

14............. ..............................................

if; (

16...........................................................

17... .........................................................

18............. ..............................................

19.. ......................................... .:... ............

20............................................................

21............................................................

22.......................

no

25............................................................

26............................................................

27..................................................... ......

28.......... .................................................

29................. ..........................................

30............................................................

31................................................ ...........

32............................................................

33............................................................

34............................................................

35...........................................................

36............................................................

37..........................................:.................

88.................................;..........................

39......................................:.....................

Salt. Lake City 

(ponds).

Length.

mm. 

16. 28 

19.26 

17.80 

22.70 

18. 24 

19.00

18.55 

Breadth.

mm. 

9.50 

10.90 

9.88 

13.26 

11.00 

11.16

10. 57 

Promontory (Brackish Springs) .

Length.

mm. 

14.74 

13. 04 

13. 00 

18.08 

18.74 

13.84 

17.34 

17.94 

18.44 

20. 64 

18. 96 

20.70 

21.20 

21.82 

18.76 

17.28 

14.42 

36.80 

15.00 

15. 82 

16. 32 

13.80 

18.56 

20.70 

18.50 

15.60 

16.20 

20.50 

21.84 

n ( ;>

15.80 

15.50

16.69

Breadth.

mm. 

7.20 

7.00 

6 16 

9.04 

8.38 

6.62 

8.40 

8.60 

8.00 

9.14 

9.40 

9.48 

9.12 

9.74

9.16 

7.68 

7.04 

7.40 

7.50 

7.10 

7..00 

6.88 

8.16 

8.88 

9.30 

7.46 

7.20 

9.50 

9.50 

7.30 

6.80 

7.78

7.90

Briefly summarized the results of the measurements are as follows.

First, the size (linear) of Pompholyoc effusa in brackish water (Pyramid Lake) is to its size in fresh water (White Pine) as 72 to 100. The 

size of Limnopliysa palustris in brackish springs (Promontory) is to its 

size in fresh water (Honey Lake) as 85 to 100. The size of Physa gyrina 

in brackish springs (Promontory) is to its size in fresh ponds (Salt 

Lake City) as 84 to 100. Brackish water is thus correlated with depauperation.

Second, comparing Pompholyx effusa from Anaho Island (Lower Lahontan), White Terrace (Upper Lahontan), and White Pine (recent), the 

ratio of size is 63: 88:100. The size ratio for Hclisoma trivolvis from 

Carson Desert (semi-fossil) and Warm Spring Lake (recent) is 56:100, 

but this is affected by the exceptional warmth of the latter locality. 

As a check recent specimens of Limnopliysapalustris from Honey Lake 

and Warm Spring Lake are compared, yielding a size ratio 89: 100. 

Depauperation is thus correlated with the Quaternary conditions.

The physiologic effects of sudden introduction of. marine mollusks 

into fresh water, or of fresh-water forms into strongly saline waters, are 

familiar. The result in either case is the death of the shells so treated.

(389)
36 MOLLUSC A OF THE GREAT BASIN. [BULL. 11.

But the shock produced by sudden transfer may be measurably avoided 

by a gradual change in the salinity or freshness of the water.

On this point Beudant long since conducted some valuable expert 

ments, the results of which have been tabulated, as follows, by Semper: 11

TABLE XII. Experiments ivith Fresh-wafer Hollusca.

Names of species.

Number theinfirst instance, May 1.on 

30 

30 

50 

50 

30 

50 

50 

50 

30 

50 

60 

50 

20 

15 

40

Number on July 15.

1. £ A 

3

21 

19 

33 

28 

22 

24 

37 

. 39 

' 23 

38 

42 

37 

17 

11 

32

0

a

C3 =M 

o 

n * 

S a

I S 

 *=

a

H

23 

17 

27 

27 

19 

31 

39 

33 

24 

35 

39 

31 

13 

10 

25

Number on October 15.

>-' . o

1

a

<a

£ 

A

16 

14 

22 

17 

15 

19 

26 

28 

21 

31 

37 

26 

8 

7 

18

* t- i-< 'oK 

0 10

fe£ « oi

e3 .

** 

,., <o £« <n <S hi >> 00 U> c3 3 

13 

11 19 

21 

13 

16 

22 

25 

11 

17 

30 

9

TABLE XIII. Experiments with Marine Mollusca.

Names of species.

Number firstin then-January stance, 1 on.

30 

50 

. 30 

30 

30 

30 

15 

30 

21 

30 

15 

20 

30 

20 

10

Number on June 1.

Inr water. sea 

23 

39 

28 

23 

26 

25 

15 

30 

19 

21 

13 

17 

24 

19 

9

In halffresn water.

21 

37 

26 

22 

23 

21 

13 

30 

21 

18 

11 

13 

21 7" 

5

Number on September 15.

In water. sea 

16 

22 

19 

17 

18 

17 

14 

30 

18 

14 

5 

11 

13 

11 

3

In quite fresh waterfifteen days. after 

15 

25 

17 

18 

15 

15 

11 

30 

19

In the first place, experiments were conducted with -reference to the 

physiologic effect of sudden transition from fresh to salt water. Subsequently, at Marseilles, the reverse experiment was tried, and numer-

"Vide Animal Life, 1881, p. 439.

(390)
CALL.] EXPERIMENTS WITH MOLLUSCA. 37

ous specimens of Mediterranean mollusca were suddenly transferred to 

fresh water. In both cases the experiments were repeatedly varied, 

until finally the results set forth in these tables were exhibited. It is, 

however, to be observed that marked increase in salinity eventually 

produced, in some instances, a result similar to sudden transfer. At 

the end of the experiments none of the fresh-water Lamellibrancbiata 

were living1 , while the Limnceidce were, on the whole, well represented. 

The experiments began on May 1 and terminated October 15. At the 

commencement 340 specimens of various limnasicl genera were placed in 

fresh water, the salinity of which was gradually increased from 0 to 4 

per cent. There were then living 140 individuals, or little more than 

41 per cent, of the whole. Of the 15 species, belonging to as many 

genera, of marine shells with which he subsequently experimented, 

commencing with January 1 and concluding September 15 following,

6 had no survivor after 15 clays in water which was quite fresh. Of 

the whole number of specimens, 391, little more than 42 per cent., 165, 

were living. One genus Mytilus represented by 30 individuals, had 

survived in undiminished numbers. Its power of endurance is seen, 

consequently, to be unusually great.

Notwithstanding several months intervened between the beginning 

and end of Beudaut's experiments, it remains to be noted that these 

conditions were produced by him within a period which, compared to 

the time required to produce in Lake Lahontan exactly equivalent conditions, was infinitesimally small. The artificial introduction of small 

quantities of salt, or of salt water, in order to induce desired changes 

in environment, could proceed with something like regularity, but in 

the great body of water composing Lahontau or Bonneville, the same 

result could be reached only through evaporation, a process extending, 

through long periods of time, during which climatal changes frequently 

intervened to freshen the gradually contracting lake. The full biologic 

expression of these changes could, therefore, only be sought in generations widely separated in point of time. During their march each succeeding generation must have acquired something of the power of resistance developed by its ancestry. But whatever of vital force was 

abstracted from the general organism to ofi'er protective aid to the 

maintenance of life, as against the new unfavorable element in environment, must have deprived some other specialized organs of full 

power to exercise their functions. "With this transfer of vital energy, 

we believe, came its biologic expression depauperation.

The final result of Beudant's experiments, in which he had marine 

and fresh-water mollusca living together in fresh water, was a condition 

which held true for certain portions of the ancient Laramie Sea of 

North America. From strata of Laramie age are described many marine and fresh-water species so associated as to necessitate the conclusion that they were co-existent. In these beds are found several species 

of Unionidw genetically related to various species now found in the

(391)
38 MOLLUSCA OF THE GREAT BASIN. [BULL. 11.

Mississippi Basin.12 TJnio is very susceptible to changes in environment, and appears to respond to them with extreme rapidity. Nevertheless, certain species live in brackish water, as seen in the Brisbane 

River, in eastern Australia, where Unio is found in stations the freshness of which is solely dependent upon the heights and times of tides. 

In the Livoniah Gulf, Cyclas, Unio, and Anodonta live associated with 

Tellina and Venus. Many species of Neritlna inhabit alike brackish 

and salt water, especially in the Philippines.13 In the La-ramie strata 

are found examples of the Strepomatidce, the specimens ranking under 

the genus Goniobasis, now exclusively confined to waters entirely fresh, 

and not found in waters close to the sea, even when abounding in the 

upper portions of many Atlantic rivers. While a full discussion of 

these and allied facts is here impracticable, sufficient data are presented 

to justify the hypothesis that increase in salinity finds a biologic expression (a) in depauperation, (b) in lessened abundance, and (c) in extinction when the water becomes briny.

DEPAUPERATION VerSUS TEMPERATURE.

There is a second factor entering into the solution of the problem 

presented by the fossils studied. This second factor, like the first, is a 

variable, but, unlike the first, reaches its extremes in far less periods 

of time. This factor is temperature. Gilbert has shown 14 that Lake 

Bonneville is the expression of a climatal episode consisting of two 

humid maxima, and, reasoning by analogy, has correlated its varying 

stages with a variable precipitation intimately connected with the temperature changes of the Quaternary and its great ice-fields. In Lahontan a similar history is exhibited by the investigations of Russell,15 and 

if the Lahoiitan tufa epochs have been correctly correlated with humidity 

epochs, ifc is also expressed by the varying abundance of Pompkolyx, as 

above indicated. In Bonnevil'.e no series of fossils, correlated with its 

varying stages, have been found, the characteristic fossils, Amnicola 

porata and A. cintinnatiensis, being found only in beds of Upper Bonueville age, and are not known to be living within the area.

The minimum temperature to which certain limnseid forms may be 

subjected, and survive, is remarkable. Limncea stagnalis has been actually frozen, but revived again on increase of temperature. A similar 

condition, or a nearly similar one, is annually produced in shallow ponds 

and ditches within the more northern United States, but every spring

12 See White on "Antiquity of certain Subordinate Types of Fresh-water and Land 

Mollusca." Am. Jour. Sci., 1830, Vol. XX, 44.

See also "Non-marine Fossil Mollnsca of North America." Third Ann. Report U. 

S. Geological Survey, pp. 472-477, 1881-'82. Also issued separately.

13 Vide Animal Life, Semper, pp. 434-435, for authorities.

14 In Second Annual Report of the U. S. Geological Survey, "Contributions to the 

History of Lake Bonneville."

15 Third Annual Report U. S. Geological Survey, "On Lake Lahontau," pp. 195-235,

(392)
CALL.] WINTER HABITS OF 39

they again teem with the old shells of the preceding years. It is matter 

of common observation, despite the pulrnonate character of the family, 

to see Physa, and Limnopliysa crawling upon the bottom of ponds wholly 

frozen over. 16 The principal effect of a lowering of temperature is complete or partial loss of power of assimilation, expressed by checks in 

growth. The lowest thermometric range compatible with assimilation 

in Limncea stagnalis was found by Semper 17 to be 12° 0. Chill-coma results whenever the temperature falls below a certain critical point, 

which varies considerably for different forms. The optimum temperature range for most fresh-water mollusca is small, bat greater for the 

Limnwidce than for any other family. The biologic expression of this 

law over wide latitudes is obvious in the varying abundance and size 

of the different forms; and analogy warrants the assumption that it 

holds true for hypsometric distribution also. But it is not necessary

to depend altogether on analogy, for there have been placed in niy

hands series of shells from springs of wide range of temperature and 

also from lakes and ponds of varying altitudes. Table XIV, together 

with Plate V, Diagram I, is based upon shells from localities of widely 

varying altitudes.

TABLE XIV. Physa ampullacea Gould.

Number.

1............. ...............................................

2............................................................

3............................................................

4 ..........................................................

5... ........................................................

6............................................................

7 ...........................................................

8 ...........................................................

9 ............................................................

10........................................:...................

12............................................................

13.............................................................

14............................................................

15 ................................................ ...........

16............................................................

17 ...........................................................

18...................................:........................

Little Gull Lake.

Length.

mm. 

11.44 

12. 50 

11.82 

12.20 

13.72 

13.22 

10.30 

13.00 

12 60 

13.76 

16.10 

15.00

Breadth.

mm. 

6.40 

9.10 

7.00 

8.00 

8.88 

9.20 

6.36 

9.32 

8.62 

8.50 

10.20 

9.44

12.97 8.45

Church Lake.

Length.

mm. 

14,18 

16.16 

18.08 

17.34 

16.22 

15.00 

14.34 

14.80 

15.50 

14.' 96 

12.62 

16.40 

13.38 

14.00 

13.60 

12.06 

14.72 

16.20

14.98

Breadth.

mm. 

9.16 

10.60 

11.58 

10.62 

10.60 

10.24 

9.44 

10.96 

10.50 

9.24 

8.80 

10.70 

8.58 

9.18 

9.24 

8.12 

8.98 

10.04

9.81

Planorbis, Limnopliysa, and Physa, from Little Gull and Parker's Lakes 

in the Mono Basin, California, at an elevation of from 7,000 to 7,500 

feet, present variant features clearly connected with station. The shells 

are exceedingly light and fragile, and below the normal size of fully

1BThe writer has also collected living Unio ventricosus, U. lateolus, and U. rubiginosus 

in the Des Moines River, Iowa, at Des Moines, in January, 1882. They were taken, 

from shallow water over a bar, the ice reaching nearly to the bottom.

17 £00. cil., p. 108.

(393)
40 MOLLUSC A OF THE GREAT BASIN. [BULL. ll.

developed adults.18 Parker's Lake is especially cold, because snow-fed ^ 

but since the most extensive series come from Little Gull Lake, measurements based upon specimens from it are alone presented. Compared 

with the same species from Church Lake, near Salt Lake City, Utahy 

with an altitude of about 4,300 feet, the average size is seen to be much 

less. The ratio of lengths is jip, and the ratio of widths 9~. Eeferring 

again to Tables IX and X, pages 33 and 34, containing the measurementsfor Helisoma trivolvis and Limnophysa palustris, additional evidence of a 

kindred nature is exhibited. In the case of the Warm Spring Lake specimens, particularly, is to be seen the effect of a higher temperature, for 

the annual mean of a small lake fed by warm springs must be always 

quite above the minimum essential for assimilation. The process of 

growth, under such favorable conditions, is either extended over greater 

periods of time or proceeds more rapidly during its continuance. This 

would appear to be almost the sole explanation of the gigantic proportions exhibited by the Warm Spring Lake specimens.

A similar effect has been noticed in Goniobasis carinifera and Goniolasis lella, both being species which abound in the brooks and springs* 

of the northern portions of Georgia and Alabama. Often, within a few 

feet of each other the one station a spring, the other a brook the difference in size is marked. Some observations made by Mr. T. H. Aldrich,. 

in north Alabama, seem to indicate that hi springs this genus does not 

hibernate as it does in brooks and rivers. The only assignable reason 

appears to be that the mean temperature of such springs does not 

widely vary.19

In only one instance has it been possible to make comparative measurements of fossils from the Bonneville area; but iii that case they are 

based upon a species now existing under circumstances quite different 

from those which probably completed the environment of the fossilswhile living. Table XVI, upon which is based Plate V, Diagram II, presents the results. The fossils are of Upper Bouneville age, and from 

beds correlated with a high stage of water, and hence of increased precipitation, the climatologic bearing of which has been above noted. 

The mean annual temperature of Utah Lake must be somewhat higher 

than that of the snow-fed Ogden Kiver; and, moreover, the lake presents the additional favorable feature of quiet water. The average of 

the Ogden River specimens is below that of those from the lake, whilethe fossils fall below both, though the fossils must have enjoyed prac18To what extent this is doe to the sum of unequal/conditions e. g., atmosphericpressure combined with lower temperature it is impossible to state. Whether suchlow organisms would respond, noticeably, to differences of barometric pressure, isdoubtful. Decrease of temperature is positively known to cause depauperation in 

some formsj and is here assumed to be the chief factor.

190n this point there is very little known. So, too, of the shell fauna of thermal 

springs. The existing data, which appear to have been exhausted by Dr. A. C. Peale* 

(in the Twelfth Annual Eeport of the Hayden Survey, pt. ii, pp. 358, 359), bear mainly 

upon vegetable forms, and in no case upon shells.

(394)
CALL.] HYPSOMETRIC DISTRIBUTION.

tically the same favorable conditions of volume, quietness^ and food asdo now their recent congeners in the lake.

TABLE XVI. Fluminicola fusca Haldeman;

Number.

1. ................................................

S.. ................. ..............................

8................................................

4.................................................

5.................................................

6.................................................

7.......................................... .

fl.......... .......................................

9.................................................

10................................................

11.................................................

12.......................................... .......

m

14.................................................

15.................................................

16. ..............................................:.

17.................................................

18.................................................

19.................................................

20.................................................

01

Z2... .............................................

23.......... .......................................

24.................................................

25.................................................

Utah Lake.

i

§ i-i

mm. 

12.50 

11.30 

10.50 

11.72 

10.10 

10.22 

10.00 

9.70 

10.50 

11.50 

9.52 

9.70 

12.00 

10.24 

10.80 

10.50 

11.90 

11.00

10. 76+

5 

101^

m

mm. 

8.10 

7. .64 

6.40 

7.14 

7.00 

G.90 

7.24 

6.52 

tf.52 

' 8.00 

7.00 

6.72 

7.80 

6.50 

8.00 

6.70 

8.20 

7.70

7.21+

Ogden River.

,d 

w> 

§ H!

mm. 

10.30 

9.36 

9.00 

8.76 

9.84 

9.80 

9.86 

10.82 

8.68 

8.70 

9.54 

8. 64 

8.12 

8.94 

9.60 

8.34 

8.70 

8.64 

8.90 

9.88 

9.78 

9.56 

8.80 

9.26 

9.04

9.24

 3 

-o

W

mm. 

6.60 

7.00 

6.62 

7.10 

6.68 

6.54 

7.10 

0.90 

6.00 

5.64 

6.80 

5.68 

5.82 

6.16 

6.50 

6.36 

5.60 

6.16 

6.40 

6.30 

7.18 

6.30 

6.00 

6.12 

6.00

6.38

Bonnovillo 

fossils.

S

fcJO a<B 

Hi

mm. 

8.10 

9.94 

9.00 

7.96 

7.58 

7.80 

9.50 

8.34 

7.94 

8.20 

8.10 

8.50 

7.60 

8.36 

8.44 

9.10 

8.08 

7.82 

7.72 

8.00 

8.30 

8.06 

7.24 

8.30 

7.46

8.23

i

T3

M

mm. 

5.50 6.62" 

5.56 

6.50 

5.40 

6.20 

6.40 

5.22 

5.50 

5.32 

5.08 

5. 5& 

5.00 

5.70 

5.60 

5.50 5.28- 

5.40 

5.38 

5.34 

6.10 

5.56 

4.98' 

5.54 

5.32

5.50-

HYPSOMETRIC DISTRIBUTION.

 » Hypsometric distribution has received from conchologists much less attention than it apparently deserves. Within small areas, comparatively, 

there are presented by hypsometry those various physical conditions 

that must otherwise be sought through several degrees of latitude. In 

this connection no extended careful investigations have been made to 

ascertain the physical conditions of the extreme heights at which some 

of our mollusca have been found. But, reasoning from analogy with 

plants and insects, the minimum of favorable conditions should obtain 

at great heights, and indeed that general fact is sufficiently indicated by 

the paucity of genera, species, and individuals at high stations. Jn 

France, however, an attemptin this direction has been made by Fischer.2* 

He discovers that the terrestrial mollusca of the Pyrenees and Alps,, 

following the analogy of plants, thrive best at certain heights, and each 

Species extends to an altitude beyond the upper limit of which it does 

not usually pass. The accompanying Table XVII is based upon hjs

20 Comptes Eendus. Tome 81, p. 624-626, 1875. 

(395)
42 MOLLUSCA OF THE GREAT BASIN. [BULL. 11.

results, in which the names of the zones as he originally applied them 

.are retained:

TABLE XVII. Hypsometric Distribution of European Mollueca.*1

05

1

w

1

»H

g

s

H

g

o

N

a

go

N 

fc

g 

O 

S)

t>

Pyrenees.

Name.

Basses valUes. lAmite superieure, 

1,000 mitres. Zone de I' Helix 

carthusiana,. 

Helix carthusiana, H. variabllis,

Mollusques fluviatiles : Neritina, 

Physa, Planorbis, Valvata, Palndina, Bithynia, Sphoerium,

De, 1,000 a 1,200 metres. Zone de, 

V Helix aspersa. 

Limax maximus, Succinea arenaria, Helix aspersa, H. lapicida, 

Pupa farinesi, P. urabilicata . . . .

De 1,200 d 1,500 metres Zone de 

I'Helix limbala. 

Limax marginatus, ZoDites cellailus, Z.fuluus, Helix limbata, 

H. hispida, Bulimus obscurus,

De 1,500 d 2,000 metres. Zone de 

I'Helix nemoralis. 

Arion erapiricorum, Limax agrestis, var. sylvatica, Helix rrrnoralis, H. rupestris, H. ericetorum, 

H. rotundata, Clausilia dubia, 

Pupa marginata, Pupa megaMollusqnes fluviatiles: Ancylus 

flu viatilis, var. capuloidea ......

De 2,000 a 2,500 metres. Zone de 

I'Helix carascalensis. 

Helix carascalensis, H. rubigena. 

Mollusques fluviatiles: Limiifca

of No.genera.

2

4

5

6 

1

1 

1

 sl

oS*%

3

6

7

10 

1

2 

1

Alps.

Name.

'Basses vallees. Limite euperieure, 

1,000 metres. Zone de I'Helix 

carthusiana. 

Succinea pntris, S. oblonga, Helix carthusiana, H. fruticum, 

H. personata, Cyclostoma eleMollusqnes fluviatiles: Physa, 

Planorbis, Paludina, Bithynia, 

Spbasrium, Unio, Anodonta ....

De 1,000 a 1,200 metres. Zone de 

I'Helix obvoluta. 

Succinea arenaria, Helix obvoluta, H. montana, H. incarnata.

De 1,200 a 1,500 metres. Zone de 

I'Hdixfontenillei. 

Zonites crystallinus. Helix ericetorum, H. fontenillei, H. lapiDe 1,500 a 2.000 metres. Zone de 

I'Helix sylvatica. 

Zonites fulvus, Helix sylvatica, 

H. rupcstris, H. rotundata, H. 

ruderata, H. hispida, Ii. ciliata, 

H. edentula, H. holosevicea, H. 

alpina, H. pomatia, OlausUia

De 2,000 d 2,500 metres. Zone de 

V Helix glacialis. 

Vitrinaglacialis, V. pellucida, V. 

nivalis, Zonites petronella, Helix placialis, H. zonata, H. 

arbustorum var. alpestris. .....

<«d

O (-1

o§ ^1

3

7

2

2

3

8

<H CO 

00

n

6

4

5

12

7

21 Tbis table is a modification of that employed by,Fischer, loc. cit. 

«,re indicated by italics.

Species common to each area

The comparatively low altitude at which certain fresh-water genera 

occur is suggestive to students of Quaternary geology, and, indeed, of 

older strata in which Unio, Anodonta, and Sphwrium occur, as indicating a probable low elevation for the waters in which they lived. To 

what extent this inference is applicable to the Laramie beds would be 

a worthy object of inquiry. The high altitudes at which representatives of the Limnceidce occurred, being found in the highest zone in the 

Pyrenees, is exactly paralleled in the Eocky Mountains and the Sierra 

Nevada, within the limits of the United States, and in Lake Titicaca 

and some other bodies of fresh water at great heights in the Andes.

(396)
CALL.] CONCLUSIONS. 43

Among land shells in North America the representatives of extreme 

hypsometric range are Pupa alticola and Vallonia pulchella the last 

being circumpolar.

The same conditions and results should not be sought within areas 

bounded by isotherms which may approximately represent the maximum or minimum temperatures between which, for any given species, 

the process of assimilation is continued, for no such inference can be 

safely drawn from isothermal lines, inasmuch as they mark the mean of 

often great extremes, either of which would prove fatal to many classes 

of mollusks and affect all. The mean of temperature does not primarily 

affect animal life, but great variations and extremes do sensibly modify 

it. Thus, the transverse irregularly distant lines or ridges in many 

inollusks, called lines of growth, indicate the cessation and subsequent 

recommencement of the process of assimilation a physiologic function 

dependent very greatly upon climate. In our climate most shells, land

and fresh water alike, hibernate during the lower temperature of winter, 

the period of harmful minimum temperature. Immediately following 

hibernation comes a period of most rapid assimilation and consequently 

of growth. This alternation continues during the life of the individual. 

But in stations where the water is below the optimum temperature, as 

in Little Gull Lake, Parker's Lake, and other similarly elevated bodies 

of water, much of the shell-forming energy is diverted to other uses, 

and there results a shell of great comparative lightness, akin to that 

seen in shells from stations deficient in calcic carbonate. The constant recurrence of this feature in shells obtained from such stations 

justifies the hypothesis that here depauperation is the consequent of a 

temperature below the optimum.

CONCLUSIONS.

Briefly summarized, the results reached by this study of the fossil 

and recent shells of the Great Basin are 

(1) That the* recent and the fossil mollusca are predominantly limnseid, a biologic expression of climate.

(2) That (a) the fossil fauna is more variable than the recent j (b) in 

the Lahoutan area being characteristically limnseid (represented by 

Pompholyx effusa), and (c) in the Bonneville area rissoid (represented 

by Amnicola porata and A. cincinnatiensis).

(3) That increase in salinity finds a biologic expression (a) in depauperation, (&) in lessened abundance, and (c) in extinction when the 

waters become .briny.

(4) That the oscillations of the lakes are coupled with (a) varying 

abundance, and (6) with varying size of shells, as a biologic expression 

of climate.

(397)
OHAPTEE III. 

DESCRIPTIONS OF NEW FORMS.

VALVATJD.E. 

Genus VALV,ATA Miiller.

Valvata sincera var. utaheusis var. nov. 

(Plate VI, Figs. 1-3.)

Testa operculata, anguste umbilicata, conica, striatula, nitida, subpellucida, apice corneo-fulva, infra albida; spira obtuse elevata, apice 

plana; sutura periinpressa; anfr. 4, regulariter accrescentes, summi 

uni-carinati, carina in anfr. inferiore evanescente, ultimo anfr. per-rotundato, £ longitudinis testae formanante; apertura circularis, postice 

subangulata; peristqma simplex, ad proximum anfr. callo tenuissimo 

juncta; intus albida.

Habitat. Lake Utah, Utah.

Long., 4.80mm ; lat., 3.20mm.

Shell operculate, narrowly umbilicate, conical, with minute transverse 

Striae, Shining, somewhat pellucid, yellowish horn color at apex, white 

below; spire obtusely elevated, flattened at tip; suture well impressed ; 

 whorls four, convex, regularly increasing, the uppermost ones with a 

single well-marked carina, which becomes obsolete on the last whorl; 

last whorl equals one-half the whole length of the shell; aperture circular slightly angled posteriorly; peristome simple, continuous, joined to 

the next whorl above by a very slight calcareous deposit; within white.

Operculum light horn color, corneus, spirally multi-volute, slightly 

produced posteriorly to conform to the shape of the aperture. Dentition unpublished.

Length, 4.80mm ; breadth, 3.20mm.

This form was dredged in August, 1883, in great numbers in Utah 

Lake, near Lehi, not far from the head of the River Jordan. It is intermediate between Valvata sincera Say and .7". virens Tryon. From the 

first it differs in. the uni-carinate upper whorls, in being more elevated^ 

in possessing a very much smaller umbilicus, and in its greater size.

44 ' (398)
CALL.] DESCRIPTIONS OF NEW FORMS. 45

From the second it differs in color, size, cariuation, and form, of aperture. It resembles, in some respects, V.umcarinala, De Kay.(=F. tricarinata Say), but differs in size, ornamentation, and form of aperture. 

Specimens may be seen in the Smithsonian Institution, in the New York 

State Museum of Natural History, and in the private collections of 

Beecher, Stearns, Dall, Aldrich, and the writer.

RISSOIM). 

Genus AMNICOLA Gould & Haldeman.

Amnicola dalli sp. nov. 

(Plate VI, Figs. 4-6.)

Testa anguste umbilicata, obtuse conica, nitida, leviter striata, fusca

vel virido-cornea; anfr. 4, convexi, leiite accrescentes; sutura regulariter 

impressa, sub-profunda; apertura ad basim rotundata, postice subaugulata, intus ca3ruleo-albida; peristoma simplex, acutum, marginibus 

crasso callo junctis; margo columellaris subreflexus. i

Long., 3.50mm ; lat., 2.30mm .

Habitat. Mountain streams, Nevada.

Shell narrowly umbilicate, obtusely conical, shining, slightly striated, 

brown or greenish horn color; whorls four, convex, gradually increasing 

in size; suture regularly impressed, somewhat deep; aperture rounded 

before, somewhat angular behind, bluish white within; lip simple, 

sharp, margins joined by a thick callous, columella rather reflexed.

Length, 3.50mm ; lat., 2.30mm.

For the diagnosis of the lingual dentition I am indebted to Mr. Charles 

B. Beecher, who has prepared the following description and illustrations :

"Jaw thin, niembranaceous.

"Odontophore J.10mm long, .13mm wide. In a full-grown example 

the odontophore has 94 transverse rows of teeth, with the formula

-3 -1 -3.

"Khachidian tooth short and broad, with the inferior lateral angles 

produced. Cusp with seven denticles, of which the central one is the 

largest. The anterior lateral faces are each furnished with a short strong 

.conical denticle, and the adjacent lateral margin of the tooth is thickened

34-14-3 and slightly produced. Formula for rhachidian tooth = "T "T .

"Body of intermediate tooth quadrate; infero-interior angle somewhat produced; furnished with a la,rge bullation, into which the inferointerior angle of the succeeding tooth appears to fit as if for articulation. 

Peduncle long and straight. Cusp with seven strong angular denticles,

-arranged according to the formula 24-14-4. s

"Body of the first lateral tooth elongate-triangular, oblique to the

(399)
46 MOLLUSCA OF THE GREAT BASIN. [BULL. 11.

direction of the broad peduncle. Cusp inflected and carrying twentythree slender denticles.

FIG. 2. Lingual dentition of Amnicola dalli, Call x 400. Beecher.

a. Two of the transverse rows of the odontophore, showing the normal position of the teeth. The 

teeth are considered as opaque. 

Analysis, b. Outer laterals, c. First laterals, d. Intermediate teeth, e. Kachidian teeth.

FIG. 3. Intermediate teeth (x 400) showing mode of articulation. Beecher.

" Outer lateral tooth hamate, with no marked distinction between the 

body and peduncle. Free extremity incurved and bearing thirty-four 

minute denticles. The denticle formula is, therefore 

3 + 1 + 3

34_23-7- 1 + 17_23-34.

"The apparent articulation of the intermediate teeth, as described 

above, was observed in a fragment of an odontophore which presented 

a lateral aspect under the microscope. It is not known that this feature has ever been noted in any other species, although it very proba-

(400)
CALL.] DESCRIPTIONS OF NEW FORMS. 47

bly occurs in many which have foraminated or bullate teeth. This 

disposition of the teeth would allow great flexion of the odontophore 

without their displacement."

This quite distinct form was collected in considerable numbers at 

Symon's Stage Station, near the foot of Pyramid Lake, Nevada. Its 

nearest congener is A.porata Say, from which it differs in elevation,. 

sculpturing, and dentition. Since this last character is the one of chief 

importance, the description of the dentition is here given. Comparing 

the denticle formulae of the two forms, thus :

A. porata.

30 _ 18 - 5 TT- 5 - 18 - 30,23 

A-, dalli.

34 _ 23 -7-^^^-7-23 -34,

the dissimilarity is strongly marked. Specimens may be seen in numerous private collections and in the cabinets of the Smithsonian Institution and the New York State Museum of Natural History.

Genus RADIX Montfort.

Radix ampla, var. utahensis, var. nov. 

(Plate VI, Figs. 7-9.)

Testa globosa, sub-umbilicata, irregulariter costata, corneo-albida, 

sub-pellucida ; spira parvula, conica; anfr. 4-4£, convexi, supra valdeplani, rapide accrescentes, ultimo inflato, cum transversis costatis perspicatis minutissime corrugatisque ; sutura sub-profunda, regulariter 

impressa; apertura elongato-ovata, effusa, intus margarita-alba; labrum simplex, marginibus callo junctis ; columella reflexiuscula, antice 

recta.

Long. 13.40mm j lat. 7.10mm.

Aper. long. 9.00mm ; aper. lat. 5.90mm.

Habitat, Lake Utah, Lehi, Utah.

Shell globose, somewhat umbilicated, irregularly costate, light horn 

color, nearly pellucid ; spire rather small, conical; whorls four to four 

and one-half, convex, somewhat flattened above, giving rather a shouldered appearance to the whorls, rapidly increasing in size, the last 

whorl being inflated, with numerous rather marked transverse costse, 

minutely wrinkled ; suture somewhat deep, regularly impressed ; aperture elongately ovate, effuse, approaching patulous, pearly white 

within 5 outer lip simple, the margin connected by a slight calcareous 

deposit ; columella somewhat twisted, but straight in front. Dentition

MAffcer Stimpson, Smithsonian Misc. Coll. No. 201, p. 14, Fig. 6; also ibid., No. 144, 

p. 80, Fig. 158.

(401)
48 MOLLUSCA OF THE GREAT BASIN. [BULL. 11.

unpublished. Length of largest specimen 16.82mm ; breadth 8.88mm. 

The average of nine specimens gave a length of 13.40mm, breadth 

7.10mm, with about the same ratio for corresponding measurements of 

aperture. Utah Lake, near Lehi, Utah.

This is a rare form in Utah Lake, its only locality so far as known. 

I'ts nearest affinity is indicated in the nomenclature adopted. In the 

preceding chapters its relation to Polyrhytis Tcingii Meek, has been 

noted. It was associated with abundant specimens of the Valvata herein 

described, and with Fluminicola fusca Hald., and Sphcerium dentatum 

Hald. Specimens may be seen as above.

Genus LYMNOPHYSA Fitzinger.

Limnophysa bonnevillensis, sp. iiov. 

(Plate VI, Figs 10-13.)

Testa umbilicata, elongata, ventricosa vel bullata, solidula, obsolete 

striata, minutissime reticulata, in anfr. infra suturam ultimo longitudinaliter obsolete costulato; spira elevata, acuta ; sutura perimpressa; 

anfr. 4-4£, per-convexi, ultimo % longitudinis testae adaequante et subito 

accresente, ventricosa, basi subexpanso; columella subplicata, leviter 

callosa, regulariter arcuata; columella peristomateque continuatis; 

peristoma simplex, marginibuscallo crassojunctis; apertura late-ovalis, 

\ totius longitudinis aequans, satis obliqua, postice angulosa.

Species fossilis, Bonneville Lake beds, Utah. Quaternary.

Shell umbilicated, elongate, ventricose or bullate, somewhat solid, 

faintly striate. and very minutely reticulated, below the suture the 

last whorl bearing faint longitudinal ridges or costae ; spire elevated, 

acute; suture deeply impressed; whorls 4 to 4£, very much rounded, 

sometimes tending to geniculation above, the last whorl equal to threefourths the whole length of the shell, rapidly increasing in size, much 

swollen, somewhat expanded at base; columella somewhat plicate, 

slightly callous, regularly arcuate; columella and peristome continuous; peristome simple, margins joined by a heavy callous which is continuous and so reflexed as to partially close the umbilicus; aperture 

broadly ovate, often patulous, equal to one-half the entire length of the 

shell, oblique, angled slightly behind.

Fossil, Quaternary. Bonneville Lake beds, Kelton, Utah.

The four largest specimens of the many in the collections give the 

following dimensions:

Specimen .

1.. ...............................................................................

2....... ............................................................................

3.................................................................................

4.................................................................................

Length.

mm. 

15.00

11.00

9 40

18.50

Breadth.

mm.

7 Rft

i en

5

OA

6.00

(402)
CALL.] DESCRIPTIONS OF NEW FORMS. 49

This shell resembles depauperate examples of L. sumassi, Baird (var. 

P. palustris Mtiller), but differs in not presenting a decussate surface, 

and in the columella being less strongly plicate. The greater number of 

specimens are somewhat malleated, though occasionally quite smooth 

specimens occur which approach nearest to L. desidiosa Say. Many 

present a patulous aperture, in which respect they resemble specimens 

of the genus Radix rather than true Limnophysa. The general outline 

of the specimens is that of L. adelince Tryon. Collected abundantly by 

Mr. Gr. K. Gilbert, in Upper Bonneville beds, at Kelton, Utah.

(403)

Bull. 11 4

INDEX.

Page. 

Aldrich, T. H,, observations by, Qn Goniolasis .............................. 40

Alps, hypsometric distribution of mollusca in the .......................... 41,42

Ancylus ................................................................... 20,23

sp. undt........................................................... 20,25

newforryi.................... ......................................20,23,28

Anotonid...................... ................................... 14,23,24,25,28,38

californiensls ...................................................... 14

nuttalliana ....................... ..-....-.. ..........14,23,24,25,28

oregonensis ............................ ............................ 14

wahlametensis ..................................................... 14

Antiquity of certain types of inollusca..................................... 38

Amnicola. ...........................................................20,23,24,28,45

cintinnatiemis ........................................20,21,24,26,28,38,43

dalli, distribution of.............................................. 21,45

dentition of................................................. 46

teeth of, articulation of ..................................... 46

compared with A. porata .................................... 47

longinqua^........ .................................................20,23,28

porata... \............................................ 21,24,26,28,38,43,47

Arion empiricorum ......................................................... 42

Assimilation a physiologic function depending on climate .................. 43

Beudant, experiments of, with mollusca.................................... 36

Bi-partite character of ice-epoch........................................... 10

Eithynia .................................................................. 42

Bulimus obacurus .......................................................... 42

Carinifex newberryi .....................................................20,23,25,28

measurements of........................................ 33

Church lake, fresh water .................................................. 31

Clausilia abietina .........................................................!, 42

dubia ............................................................. 42

Conulus fulvus ............................................................ 24,25

CorUculidce........ .................................................. 15,23,24,25,28

Cyclas .................................................................... 38

Cyclostoma elegans ......................................................... 42

Cyprinidce ................................................................. 23

Oypris sp.................................................................. 23

Depauperation, a biologic expression of transfer of energy ................. 37

versus salinity .............................................. 30

Distribution of fresh-water shells, table of................................. 28

European mollusca, hypsometric distribution of............................ 42

Experiments with fresh-water mollusca..................................... 36

marine mollusca ........................................ 36

51

(405)
52 INDEX.

9 . ' Page. 

Fischer, hypsometric distribution of mbllusca.............................. 41,42

Fluminicola .........................................................21,23,24,25,28

fusca. .............................................13,21,23,24,25,28,48

measurements of.......................................... 41

 Fossil mollusca, Lahontan................................................. 23

Bonneville................................................ 24

 Gasteropoda ............................................................... 16

 Genera of fresh-water mollusca; live at low altitudes ...................... 42

^Gilbert, G. K. Investigation of Lake Bonneville........................... 10

Contributions to the History of Lake Bonneville............ 12

v Eeport on the Geology of the Great Basin, etc .............. 11

Sketch of Quaternary lakes ................................ 9

Glacial climate............................................................ 10

Goniobasis. ................................................................ 38

tella ............................................................ 40

carinifera..... ................................................... 40

winter habits of................................................. 40

Great Salt Lake, salinity of................................................ 31

Gyraulua..............................:..................../......... 16,23,24,25,28

parvus .....................................................16,23,24,25,28

vermicularis ................................................... 17,23,24,28

HelicidcB ...............................................................22,23,24.25

Rdiaoma. ......................................................... 16,17,23,24,25,28

ammon .....................................................16,17,23,24,28

corpulentua ........................................................ '24,28

plexata ........................................................... 29

subcrenatus ....................................................... 24,28

trivolvis ........................................... 13,16.23,24,25,28,35,40

measurements of.......................................... 33

Helix alpina ............................................................... 42

arbustorum, var. alpestris ............................................ 42

 'aspersa.... .......................................................... 42

dliata .............................................................. 42

varawalensia........ ...J............................................. 42

carthusiana ........................................................... 42

edentula ............................................................. 42

ericetomm ........................................................... 42

fontenillei ........................................................... ' 42

fruticum ............................................................ 42

glacialis.............................................................. 42

hispida".............................................................. 42

holosericea ........................................................... 42

incarnate................ ............................................ 42

lapicida ............................................................. . 42

limbata ............................................................. 42

montana ................................................. ^............ 42

nemoralia ............................................................ 42

oZwoZwto ............................................................. 42

palustris ................................... ..........'................ 17

personata............................................................ 42

pomatia ............................................................. 42

l«tZcMZa............................................................ 22,42

rotundata ........................................................... 42

(406)
INDEX. 53

	Page. 

Helix rubigena. ...... ; ..... .......................................... ...... ' 42

ruderata...... ................ .^.. ................................... 42

rupestris ............................................................. 42

sylvatica ... 1 ........................................................ 42

variabilis .............................. .............................. 42

sonata .............................................................. 42

Ho well, E. E. Eeport on the Geology of the Great Basin, etc .............. 11

Hyatt, on Steinheira Planorbis ....................................... .\.... 27

Hypsometric distribution of mollusca.... ................ .... .... .... ...... 41

range, mollusca of extreme. .................................. ' 43

Ingersoll, on Helisoma plexata .............................................. 29

/

King, Clarence, Studies of, in the Great Basin .............................. 9

Systematic Geology ....................................... 12

Lacustrine deposits ....................................................... 9

Lamellibranchiata, fresh- water, sensibility of ................... '. .......... 37

Laramie Sea, Unionidceiu the.... .......................................... 37

Leuchocheila arizonensis .................................................... 24

Limncea.. ........................................................ 17, 24, 28, 36, 38, 42

auricularis ......................................................... . 36

luniosa var. glacialis ...... .......................................... 42

palustris ........................................................... 36

frozen. .................................................... 38

species circumboreal ............................................... 29

lAmncBidce. .............. ............................. 13, 16, 23, 24, 25, 28, 29, 37, 39, 47

hypsometric distribution of ...................................... 42

Limnophysa... ................................ ........17,23,24,25,28,30,31,39,48,49

adelince ....................'........'........................ .... 49

lonnevill&nsis..... ....................................... ....18,24,28,48

description of ..................................... 48

measurements of .................................. 49

relations of ....................................... .. 49

bulimoides ........................................ ....'...... 18, 23, 24, 28

oaperata ........................... .............'............... 25

desidiosa ....................................................... 24,49

Jiumilis ....... ............ ...... ........................ .18,23,24,25,28

palnstris. ............ ............ ...... 13, 17, 18, 23, 24, 25, 88, 29, 35, 40, 49

measurements of ........................... ............ 34

sumassi ................. ...! ... .................. ..17,23,24,25,28,29, 41>

winter habits of ............................................... 391

Limax agrestis, var. sylvatica. ............................................... 42

maximus ............................................................ 42:

marginatus ....................................... ..........»......!. 42-

Little Gull Lake, fresh-water...... .......'................................. 31

Margaritana .................................................... ....14,23,24,25,28

margaritifwa...... ................................ ......14,23,24,25,28

Menetus opercularis .................................................. 17, 23, 24, 25, 28

Mytilm ................................................................... 37

powers of endurance of ............................................ 37

Nerilina .................................................................. 38-

(407) f
54 INDEX.

Page. 

Ostracoda ................................................................. 23

Paludina .................................................................. 42

Patula hemphilli ..............................................- . 4........... 24

idahoenm .......................................................... 24,25

strigosa .........................................'................... 24,25

Physa...... ........................... ...................18,24,25,28,30,31,39,42

* ampullacea......... .............................................. 19,24,25,28

measurements of.......................................... 39

.elliptica. .......................................................i .. 28

gfj/nwa .........A.:..............................................18, 24,25,28

measurements of............................................... 35

heterostropha ........................... I............. ......'......18,24,25,28

humerosa ............................................................. 24

Zordi.............................................................19,24,28,29

winter habits of .... ................................................ 39

Physiologic effects of decreased temperature................................ 39

Pisidium ....... ................................................. ......15,23,24,25,28

dbditwm... ........................................................16,25,28

ccMftpresswm.................................................. 15,23,24,25,28

ultramontanum .................................................... 15,23

Planorbis ..............................................................27,29,36,42

carinaius .................................................. ...... 36

corneus ................................................ .......... 36

vortex............................................................ 36

memoir on Steinheim ............................................ 27

Polyrkytis kingii...... ........... ..*.................;.....................19,27,48

Pomatiopsis ............................................................... 27

Pompholices ...........................1................................... 30

Pompholyx ...................... ..............................19,23,24,28,30,31,34

occurrence of, in tufa ........................................... 26

variations of................... ................................ 27

oostata .......... ........................................... ..*.. 19

e/usa...................... .....................19,23,24,28,31,32,35,43

related to Vorticifex Unneyi................................ 27

'vai.solida......... ........................................19,27,32

characteristic of Lahontan deposits......... '. .............. 26

dimensions of............'.................................. 31,32

Post Bonneville, defined................................................... 10

Lahontan, denned ...... ............................................. 10

Powell, J. W., Studies of, in the Great Basin ............................... 9

Pulmonatageophila ........................................................ 22

Pupa ..................................................................... 42

farinesi .............................................................. 42

marginata...... ...................................................... 42

megacheilos...... ..................................................... 42

muscorum ............................................................22,23, 24

umUlicata ........................................................... 42

Pupidce ...................................................................22,23,24

Pupilla .................................................................. 22,23

alticola ............................................................ 43

corpulenta ........................................................ 24

murcorum......... ................................................ 22,24

Pyramid Lake, salinity of...... ........................................... 31

Pyrenees, hypsometric distribution of mollusca in the ...................... 41,42

(408)
INDEX. 55

Page.

Pyrgula, genus new to North America...................................... 27

nevadensis........ .................................... 21,23,24,26,27,28,30

scalariformis...................................................... 27

Pyrgula scalariformis, a doubtful form ...................................... 27

distribution of.................................................... 27

Radix..... .............................................................19,25,47,49

ampla ....s:......................................................... 19

var. utah&nsis. ............................................ 19,25,27,28

distribution of........................;....... 19,47

description of................................. 47

related to Polyrhytis Mngii.....................'.. .............. 27

Eecent mollusca, Bonneville............................................... 24

Lahontan ................. .............. ................ 25

Eesults of measurements of shells summarized.............................. 35

^«0^........................j........................-..13,20,23,24,25,26,27,45

Russell, I. C. Monograph of Lake Lahontau ................................ 11

Sketch of the Geologic History of Lake Lahountan ........... 12

Southern Oregon, a Geological Reconnaissance in ............ 12

Salinities of Lakes of Great Basin.........../.............................. 31

Salinity, physiologic effects of.............................................. 34

Semi-fossil denned ........................................................ 10

Sphcerium.... .......................................................15,23,24,25,28

dentatum .... ...........................................15,23,24,25,28,48

striatinum .................................................15,23,24,25,28

Springs, chemical constitution of, variable................................. 30

Stansbury, Report on Great Salt Lake..................................... 30

Sirepomatidce.... .......................................................... 29,38

Auctinea.... ........................................................22,23,24,25,42

arenaria .......................................................... 42

lineata.... ........................................................ 24,25

oblonga ........................................................... 42

putris............................................................. 42

rusticana .. ....................................................... 24

sillimani. .... ..................................................... 24,25

stretcMana ........................................................22,23,24

Summary of measurements of shells........................................ 35

TelUna........................ ............................................ / 38

Temperature decreased, physiologic effects of.............................. 39

Thermal springs, absence of shells in....................................... 40

Tufa...................................................................... 26

dendritic............................................................. 11

lithoid...... ......................................................... 11

thinolite............................................................. 11

Unconformity of lacustrine deposits ....................................... 9

tufas..................................................... 11

Unio........... ........................................................... 38

susceptibility of.......:.............................................. 38

luteolus, winter habits of.............................................. 39

ruMginosus, winter habits of .......................................... 39

ventricosua, winter habits of .......... ................................. 39

(409)
56 INDEX.

Page. 

Unionidce.... ................. ......................................14,23,24,25,37

Valvata. ......................................................21,23,24,25,28,44,48

Valvata sincera ..............................................^............. 22,44

v&T.utahensia ............................................22,24,25,28

description of.................................. 44

distribution of................................. 22,44

tricarinata...... ..................................................: 45

unicarinata .............................. .......................... 45

virens v .............................. ..*........................21,23,28,44

Valvatidce... .....................................................21,23,24,25,28,44

Vallonia ..................................................................22,23,24

minuta ........................................................... 22

pulchella... \................................................... 22,23,24,43

V&nua......................... ............................................ 38

Vertigo ovata .............................................................. 25

Vitrinaglacialis ................................. 1 ......................... 42

wivaZis............................................................. 42

pellucida ........................................................... 42

p/ej^en............................................................ 24,25

VorticifexUnneyi, relations of.............................................. 27

Walker Lake, absence of Pyrgula living in................................. 26

salinity, percentage ........................................ . 30

Wheeler, George M., Studies of, in the Great Basin......................... 9

White, C. A. Antiquity of certain types of mollnsca........................ 38

v Non-marine Fossil Mollusca ................................. 38

Winter habits of Goniobasis................................................ 40

Limnophysa .............................................. 39

Physa...... .............................................. 39

Zonitea arborcus ........................................................... 24

cellarius .... ....................................................... 42

cryatallinw..... .................................................... 42

fulvus.............................................................. 42

nitidut........................ ..................................... 24

petronella ................................,.,. ...................... 42

viridulus ........................................................... 24

(410)

PLATE II.

Each conventional sign represents a shell, and its position represents the dimensions 

of the shell. The lengths are found by reading from below upwards; the breadths by 

reading from left to right. The marginal numbers represent millimeters.

The average of the giveu series is represented by the closed conventional sign.

DIAGRAM 1.

Based upon Table VI, page 31. Pompholyx effusa Lea.

The circles represent specimens from Pyramid Lake, Nevada; the squares specimens from White Pine, Nevada.

DIAGRAM 2.

Based upon Table VII, page 32. Pmnpholyx effusa Lea.

The circles represent fossil shells from the gray tufa, Anaho Island, Pyramid Lake, 

Nevada; the squares fossil shells from the marl at White Terrace; and the triangles 

represent living shells from Pyramid Lake, Nevada.

58 (412)
II. 8. GEOLOGICAL SURVEY BULLETIN NO. 11 PL. II

DIAGRAM I.

8 40

DIAGRAM II.

i I I.I

3 , 4 10

COMPAKATIVE DIMENSIONS OF POMPHOLYX EFFUSA
PLATE III.

Each conventional sign represents a shell. The lengths are found by reading from 

below upwards; the breadths, by reading from left to right. The marginal numbers 

represent millimeters. '

The average of the given series is represented by the closed conventional sign.

DIAGRAM 1.

Based upon Table VIII, page 32. Carinifex newberryi Lea.

The circles indicate fossil specimens from the south end of Winnemucca Lake, Nevada ; the squares represent semi-fossil shells from Christmas Lakes, Oregon.

DIAGRAM 2.

Based upon Table IX, page 33. Hettsoma trivolvis Say.

The circles indicate shells from Warm Spring Lake, Utah; the squares, semi-fossils 

from Carson Desert, Nevada.

60 (414)
If. 8. GEOLOGICAL BURVKY UULLKTIN NO. 11 PL. Ill

DIAGRAM I.

_.__[_

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H--0- 4-4 ± it

x

X

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4-

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DIAGRAM II.

i

A P. " X 4 _h

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COMPARATIVE DIMENSIONS OF SHELLS
PLATE IV.

Each conventional sign represents a shell. The lengths are found by reading from 

below upwards; the breadths, by reading from left to right. The marginal numbers 

represent millimeters.

The average of the given series is represented by the closed conventional sign.

DIAGRAM 1.

Based upon Table X, page 34. Limnophysa palustris Mull.

The circles represent specimens from Honey Lake, California; the squares, shells, 

from Warm Spring Lake, Utah; and the triangles, specimens from brackish springs, 

Promontory, Utah.

DIAGRAM 2.

Based upon Table XI, pages 34 and 35. Physa gyrina Say.

The circles represent shells from brackish springs, Promontory, Utah ; the squares, 

specimens from fresh-water ponds at Salt Lake City, Utah.

62 - (416)
U. 8. GEOLOGICAL SURVEY BULLETIN NO. 11 PL. IV

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COMPAKATIVE DIMENSIONS OF SHELLS FHOAI FUKSII AND BRACKISH STATIONS
PLATE V.

Each conventional sign represents a shell. The lengths are found by reading from 

below upwards; the breadths, by reading from left to right. 'The marginal numbers 

represent millimeters. *

The average of the given series is represented by the closed conventional sign.

DIAGRAM 1.

Based upon Table XIV, page 39. Physa ampullacea Gould.

The circles represent shells from Little Gull Lake, California; the squares represent 

shells from Church Lake, near Salt Lake City, Utah.

DIAGRAM 2.

Based upon Table XVI, page 41. Fluminicola fusca Hald.

The circles represent fossils from Kelton, Utah; the squares, shells from Ogden 

River; and the triangles, specimens from Utah Lake, Utah.

64 (418)
U. S. GKOLOOICAI. BUKVEY UULLKTIN NO. 11 VL. V

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PLATE VI. .

Page. 

Valvatasincera, var. utahenais ........ ....... ........................... 44

Fig. 1. Front.

Fig. 2. Top.

Fig. 3. Back. 

Amnioola dalli. .............................................................. 45

Fig. 4. Front.

Fig. 5. Top.

Fig. 6. Back. 

Radix ampla, Tar. utahensis .................................................. 47

Fig. 7. Front.

Fig. 8. Top.

Fig. 9. Back. 

Limnophysa bonnevillensis. .................................................... 46

Fig, 10. Front.

Fig. 11. Top.

Fig. 12. Back.

Fig. 13. Smooth individual; front. 

66 (420)
U. S. GEOLOGICAL SURVKY BULLETIN NO. 11 PL. VI

HKCKNT AND QITATEHNAKY MOLLUSCA,