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UNITED STATES DEPARTMENT OF THE INTERIOR

PLIOCENE DIATOMS

FROM THE

KETTLEMAN HILLS, CALIFORNIA

GEOLOGICAL SURVEY PROFESSIONAL PAPER 189—C
UNITED STATES DEPARTMENT OF THE INTERIOR 

Harold L. Ickes, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall, Director

Professional Paper 189—C

PLIOCENE DIATOMS

FROM THE

KETTLEMAN HILLS, CALIFORNIA

BY

K. E. LOHMAN

Shorter contributions to general geology, 1937

(Pages 81-102)

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1938

For sale by the Superintendent of Documents, Washington, D. C. - - - - Price 15 cents
CONTENTS

	Page 

Abstract_ -_--__-___________-_--_-__-_______________-_______________________-_-_____--.__-____--_--__-________ 81

Introduction,_________________________________________________________________________________________________ 81

Stratigraphy and diatom floras.______...--_______-__________-_______-_______-___-___---.---__------_--..__-_----__- 85

Etchegoin formation-_____-___-_-__-_____ __________________________________________________________________ 85

Lower part.____--__-_____-_-.__________________________-________-__-___---_--__-_-_---_____________- 85

Upper part..-_ ___________________________________________________________________________________________ 86

San Joaquin formation___-.______-_____-_____________-__-______--__________-___--______---_--___________-__- 87

Neverita zone....______________________________________________________________________________________ 87

Tuffaceous sandstone overlying Neventa zone____________________________________________________________ 88

Tulare formation._____-__-_--_--__-__-_____,__--_-._-___-_-_-_-_--________-__.---_--_--___-___-_______-_-.- 88

Descriptions of new species._______________'__-_____-___-________-_--_-___-_--__-____--_-___-____-___-__-_______- 90

Index.._______________________________ _______________ __________________________________________________ 101

ILLUSTRATIONS

Page 

PLATE 20. Diatoms from the Etchegoin formation of South Dome, Kettleman Hills. _______________________________ 96

21, 22. Diatoms from the Neverita zone and overlying tuffaceous sandstone and clay of the San Joaquin formation,

Kettleman Hills_______.__.._..___________-.___.______.__._______.____..________._____.__.._. 97,98

23. Diatoms from the Tulare formation, Kettleman Hills_________._________-__-_______-___-____--_---.- 99
PLIOCENE DIATOMS FROM THE KETTLEMAN HILLS, CALIFORNIA

By K. E. LOHMAN

ABSTRACT

The Kettleman Hills form a range of foothills about 30 miles 

long and 4 to 5 miles wide on the western edge of San Joaquin 

Valley, Calif., about 75 miles northwest of Bakersfield. Two 

marine Pliocene formations, the Etchegoin and the San Joaquin, 

and one brackish- and fresh-water Pliocene and Pleistocene (?) 

formation, the Tulare, crop out in the hills. A total of 232 

species and varieties of diatoms were obtained from the three 

formations, all from beds assigned to the Pliocene. These are 

listed according to their distribution and abundance. Characteristic groups from each formation are illustrated, and their 

stratigraphic and ecologic significance is discussed. Five new 

species are described and figured.

INTRODUCTION

The Kettleman Hills form a low-lying range of foothills of the Coast Range about 30 miles long and 4 to 

5 miles wide, on the western edge of San Joaquin Valley, 

Calif., about 75 miles northwest of Bakersfield. The 

line dividing Kings County on the southeast from 

Fresno County on the northwest passes through the 

northwest end of the hills. They are divided into three 

structural and topographic units—the North, Middle, 

and South Domes.

W. P. Woodring and Ralph Stewart, of the United 

States Geological Survey, while engaged in mapping 

the Kettleman Hills, collected samples from beds that 

gave promise of containing diatoms and submitted 

them to me for study. I have visited most of the 

localities and collected two of the samples studied for 

this report. Acknowledgment is due to Mr. Woodring 

for many valuable suggestions and much information 

concerning the geology and stratigraphy of the Kettleman Hills.

A total of 232 species and varieties of diatoms, 

including 5 new species, were found in 12 samples 

representing the three formations exposed in the hills. 

Most of the diatoms are represented in living floras,

150226—38

but some are extinct forms and appear to have had 

short ranges in geologic time. Three formations— 

the Etchegoin, San Joaquin, and Tulare (named in 

ascending order)—crop out in the Kettleman Bills, 

and diatoms were collected from all three formations. 

The Etchegoin and San Joaquin and the lower part of 

the Tulare (the part from which diatoms were collected) 

are assigned to the Pliocene, and the upper part of the 

Tulare is doubtfully assigned to the Pleistocene.

A complete check list of the diatoms found in the 

Kettleman Hills as a result of the present study is 

given in the accompanying table, together with their 

relative abundance indicated by the following symbols: 

R, rare; F, few; C, common; A, abundant. Tl ?>se 

symbols have no exact numeripal significance but are 

fairly comparable, as all the samples received approximately the same degree of condensation in their prep^ration and mounting. It is believed that this gives a 

much better picture of the flora as a whole and of the 

relative value of the various species for purposes of 

ecology or correlation than is obtained by merely 

listing the species as present. This is particularly true 

when an attempt is made to obtain some idea of the 

ecologic conditions which the various floras represent.

The diatoms indicate a change from marine deposition in the older beds to brackish-water and freshwater deposition in the younger beds. Certain I Q.ds 

were found to contain diagnostic species ( which were 

not found in any of the other beds studied. These are 

discussed under the different stratigraphic units.

The geology of the Kettleman Hills is discussed in a 

report now in preparation by W. P. Woodring, R^lph 

Stewart, and R. W. Richards. The present paper, 

therefore, contains only general statements regarding 

the stratigraphy.

81
82 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1937 

Pliocene diatoms from Kettleman Hills, Calif.

Melosira sulcata (Ehrenberg) Kiitzing (pi. 22, fig. 15) ________ _

recedens Schmidt (pi. 22, figs. 13, 14) _ _._. ____ __ _ __

polaris Grunow _____ ____________ _______ _ _ _ ___

cf . M. clavigera Grunow ___ ____ _ ______ ____

undulata (Ehrenberg) Kiitzing var. normanii Arnott. ______

solida Eulenstein. __ _ _ ____ ___ _____ __ _____ ___

solida var. haitiensis Grunow. __ _ ______

solida var. multiformis Frenguelli___ ___ _ __ ____

distans Kiitzing var. lirata (Ehrenberg) Bethge._____

granulata (Ehrenberg) Ralf s (pi. 23, fig. 8) _ _ _______

granulata var. curvata Grunow (pi. 23, fig. 7)_____ ___ __

granulata var. australiensis Grunow_ _______ ____ _ _

granulata var. muzzanensis (Meister) Bethge. _ ____ ____ __

cf. M. islandica Miiller _______ _ _ _ _______ __ __

italica (Ehrenberg) Kiitzing __________ ____ ___

ambigua (Grunow) Miiller (pi. 23, fig. 9) __ . __ _ __ __

Podosira hormoides (Montagne) Kiitzing var. adriatica Grunow_____

stelliger (Bailey) Mann_________ _ _________ _ ___ ___

febigeri Grunow _ _ _____ __ _________

Hyalodiscus schmidtii Frenguelli (pi. 23, fig. 5)_____ __

Stephanopyxis turris (Greville and Arnott) Ralfs______ _ _

turris var. cylindrus Grunow. _ __ ___ ____

corona (Ehrenberg) Grunow (pi. 22, fig. 2)_ __

bruni Schmidt var. _______ _ ____________ ___

Endictya oceanica Ehrenberg- ______ ______________

robusta (Greville) Hanna and Grant (pi. 20, fig. 4)___ _ __

striata (Kiitzing) Grunow______ ___ ______ ____

compta (Ehrenberg) Kiitzing var. pliocaenica Krasske. ___

iris Brun and He>ibaud___ _ _ .___ __ _ _ _____ __ ___

pygmaea Pantocsek___ ______ ______________ _____

Stephanodiscus dubius (Fricke) Hustedt (pi. 20, fig. 10) ______ ___

astraea (Ehrenberg) Grunow _______ ___ _ __

carconensis Grunow (pi. 23, fig. 2)__ ____

carconensis var. pusilla Grunow __ ___ ____

Coscinodiscus excentricus Ehrenberg (pi. 20, fig. 5; pi. 21, fig. 5)_ _

anguste-lineatus Schmidt- ___ _______ ___ ___ _ ___

lineatus Ehrenberg____ __ ___ _____ ____

stellaris Roper _____ ___ _______ _____

subtilis Ehrenberg (pi. 21, fig. 6)_ _ _____ ___

kutzingii Schmidt _ ___ _ ._ ____ __ ____ _ __

cirrus Lohman, n. sp. (pi. 21, fig. 4) _______

spinuligerus Rattray_____ _ __ __ _____ ___ _____

bisculptus Rattray____ __ ___ _ _ ______ _ _______

vetustissimus Pantocsek (pi. 20, fig. 7)___ ______ _ ____

curvatulus Grunow____ _ _________ ____ ___

inclusus Rattray (pi. 20, fig. 3) ____________ ___ _ _ _

denarius Schmidt _ _ _ _ ____ _ _______ _ _ ____

rothii (Ehrenberg) Grunow var. normani (Gregory) Van 

Heurck____ ___ _ ______ _____ _____________ __

obscurus Schmidt (pi. 21, fig. !)___ ______ _ _ ___ __

radiatus Ehrenberg- _______ ____ _____ _ ______

gigas Ehrenberg ________ _ __________ ____ __ _

boliviensis Grunow ______ _ _______ _ ____

cf. C. janischii Schmidt- ____ _ _____ ___

biangulatus Schmidt- __ _____ __ _______ _ _ ____

asteromphalus Ehrenberg (pi. 21, fig. 3)__

asteromphalus var. omphalantha (Ehrenberg) Grunow 

(pi. 20, fig. 2)____________________________________

oculus-iridis Ehrenberg______ _ _ ______

pacificus Grunow ___ __ ___ _ ___

kurzii Grunow (pi. 20, fig. 1; pi. 21, fig. 2)_ _ _ .

cf. C. elegans Greville ______ ___________ _ ____

cf. C. cribrosus Truan and Witt___ ______ ___

Actinoptychus splendens (Shadbolt) Ralfs var _ __ _____

undulatus Ehrenberg (pi. 20, fig. 8; pi. 22, fig. 3)_._ __.

cf. A. areolatus Ehrenberg ____ __ _______ _____ _ _

sp — _ _ _ _ ________ _____ _ __ _______ ___ ___

Arachnoidiscus cf. A. ehrenbergii Bailey _ __ ___

Asteromphalus brookei Bailev ___ __________ _ _____ ____

Tulare formation

1061

F

R

R

F

839 838

F

F

C 

F

R

C

F

F

F

R

F

F

C

C

R

1053

F

R

R,

A

F

F

R

A

F 

C

R,

R

R

San Joaquin formation

Tuffaceous 

sandstone

1054

F

R

R

F

C

C

F 

F

F 

R

F

F

F

R

F 

R

C 

R

C

R

1056

C

A 

F

R

R

R?

R

——

F

F

F

F

F

C

F

C 

F

1057

C

c

R

F

F

F

F

R

F 

R

F

F 

F 

F

F

F

F

C

R

Neverita 

zone

1052

C 

F

R 

R

R

F

F

C

"F"

F 

F 

C

R

R

F 

F 

C

R

C 

C

F

F

A

1051

F 

R

R

R

R

R

F

F

R

R

C

F 

R 

F

C 

F

R

C 

F

F 

C

F

C

R,

Etchegoin 

formation

Upper 

part

1058

R

R

R

R

R

R

R

F

F

A

F

F

R

F

R

----

F

C

A

Lower part

1117

F

____

F

——

F

1060

-___

R

R 

R

R

F

F

——

F

C

C

F

F

F 

R 

C
PLIOCENE DIATOMS FROM THE KETTLEMAN HILLS, CALIFORNIA

Pliocene diatoms from Kettleman Hills, Calif.—Continued

83

ehrenbergii var. ralfsii (W. Smith) Hustedt___ ______

Bacteriastrum hyalinum Lauder_ _ ___ _________ ________

Omphalotheca sp __ _ ._ _ __ ________

Hercotheca cf. H. mammillaris Ehrenberg/

cf. B. reticulata Roper __ _ ___________

angularis Lohman, n. sp. (pi. 22, figs. 6, 7, 8)__ ________

fatula Lohman, n. sp. (pi. 22, fig. 5)____ ______________

pectinalis (Kutzing) Rabenhorst- __ _.__ ___ _________ ._

pectinalis var. undulata (Ralfs) Rabenhorst _________ ___

cf. E. gradlis (Ehrenberg) Rabenhorst- ______ ____________

cf. E. didyma Grunow var. curia Hustedt_ __ _____________

Rhoicosvhenia curvata (Kutzine) Grunow _______ _ ____________ „_

Tulare formation

1061

t

F

839

C

838

F 

R,

R

R

R

R

R,

R

F

F 

F 

R 

R,

R

R,

R,

R,

F

F

F 

R

F

1053

R

F 

R

F

R

F

R,

R

R

____

R

R

F 

R

San Joaquin formation

Tuffaceous 

sandstone

1054

R

F

F

F 

F 

R

F

C

R

F 

F

R

C

R

F

F

F

F

F

R

R

----

R,

1056

C

c

R

R

R 

R 

R,

F

R

C

R

R

1057

A

----

R

F

----

R

R

R

C

F

C

R

Neverita 

zone

1052

R,

F

F 

C

R

F 

R

F

F

F

F

F

1051

R

C

F

F

R

F

F

F

F

Etchegein 

formation

Upper 

part

1058

F 

F 

F

R,

F

F

R

R

R

F 

R,

F

F

Lower part

1117

———

----

1060

C

F

F

R

R 

F 

F 

C

R

A 

R

R
84 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1937

Pliocene diatoms from Kettleman Hills, Calif.—Continued

Mastogloia elliptica Agardh___ ___ __ ____ _ __ _ ___' _ _ _

Caloneis cf . C. formosa (Gregory) Cleve _______

formosa var. rostrata Frenguelli _ _

silicula (Ehrenberg) Cleve var. kjellmaniana (Grunow) Cleve _ 

trinodis (Lewis) Meister___________ _ ___ _ _

Stauroneis phoenicenteron Ehrenberg _ ____

cf . S. anceps Ehrenberg var. gracilis Ehrenberg _ _

parvula Grunow _______ _____

Navicula cf. N. cuspidata Kutzing _ _ _____ ____ _ __ _________

pupula Ktitzing var. capitata Hustedt _ ______

pupula var. rostrata Hustedt- _ ___ _ __ ______

radiosa Kutzing _ __ ___ _ _ _ _ __ ___

radiosa var. tenella Brebisson ____ ____ ___________

pennata Schmidt (pi. 22, fig. 16) _ _ __ ______

pennata var. kinkeri Pantocsek____ _ _____

peregrina (Ehrenberg) Kutzing var ___ ___ ___

gastrum Ehrenberg-- _ _______ ______

exigua (Gregory) 0. Muller_ _ _ _

cf. N. subtilissima Cleve ______ __ ______

tuscula Ehrenberg- _ _ _ ______

amphibola Cleve_ ___ _____ ____ ________

marina Ralfs (pi. 23, fig. 13) _ _ _______ _______ __ ___

lyra Ehrenberg _______ ______ ____ __

hennedyi W. Smith-. __ _____ ___ ________

clavata Gregory var. elliptica Schmidt (pi. 20, fig. 9) _ _ _ _ _

Pinnularia cf. P. subcapitata Gregory _ ___ _____

borealis Ehrenberg- __ __ ____ ____ ___

major (Kutzing) Cleve___ _ ____ _____

cf. P. major var. subacuta (Ehrenberg) Cleve ___ _ _ _

dactylus Ehrenberg ___ ___________

cf. P. viridis (Nitzsch) Ehrenberg _ ____

nobilis Ehrenberg ____ ___

fasciata (Lagerstedt) Hustedt- _ ___ _ ______ _

hemiptera Kutzing- __ _____ ____ ________

ovalis var. libyca (Ehrenberg) Cleve ___ _

affinis Kutzing__ __ _ __ _ _______ _____

Cymbella cuspidata Kutzing ____ ____ ____ __________

prostrata (Berkeley) Cleve (pi. 23, fig. 15) _ _ _

ventricosa Ktitzing__ __ ___ _______ ___

cymbiformis (Ktitzing) Brebisson. ___ _ _ _____

parva (W. Smith) Van Heurck_ __ ______ _______

cistula (Hemprich) Kirchner _ ____ ___ _ ________

lanceolata (Ehrenberg) Kirchner _ ___ _ ______ _

mexicana (Ehrenberg) Cleve (pi. 23, fig. 14) _ _'___ _ _

Gomphonema acuminatum Ehrenberg var. turris Ehrenberg __ _ _

augur Ehrenberg var. gauteri Van Heurck____

intricatum Kutzing __ __________ ______

constrictum Ehrenberg- __ __ ___ ______

scapha M. Schmidt _ _ __ ____ ___ _ ____ ___

Gomphoneis mamilla (Ehrenberg) Cleve ___ ____

herculeana (Ehrenberg) Cleve _ ______

cf. G. herculeana var. robusta Grunow__ ___ ____

elegans (Grunow) Cleve _ _ _ _ _ _

Epithemia argus (Ehrenberg) Ktitzing- _ _ _ _

zebra (Ehrenberg) Ktitzing _ _____ ____ _ ___ ____ _

zebra var. saxonica (Kutzing) Grunow (pi. 23, fig. 3)__ ____ 

zebra var. porcellus (Kutzing) Grunow __ _______ __

turgida (Ehrenberg) Kutzing (pi. 22, fig. 4) _ _____

turgida var. granulata (Ehrenberg) Grunow _ ___

turgida var. westermanni (Ehrenberg) Grunow _ _ _ _ _

sorex Kutzing ______ _ _ __

Rhopalodia gibba (Ehrenberg) Mtiller (pi. 23, fig. 4)

gibba var. ventricosa (Ehrenberg) M tiller. _ ______

gibberula (Ehrenberg) Muller_._ __ __ _ ______• _ _

Tulare formation

1061

F

R

R,

R,

R,

R,

R

F

A

C

C

839

C

C

C 

F

F

838

F 

R

R 

R 

R,

F

F

R 

F

R

F 

F

F

F 

R 

R

R 

R,

R,

F

F

R,

R,

F

R

R,

R 

R

F 

R,

R,

R,

F

R,

F

R 

R

R 

F

R 

F 

F

F 

R,

F

F 

F

1053

A

R

R

R

R 

R

C

R

R,

F

F

R 

R

F

R

R

F 

R 

F

F

San Joaquin formation

Tuffaceous 

sandstone

1054

R

F

F

R

R

1056

R,

F

R

1057

F

F 

R,

Neverita 

zone

1052

F

R

1051

Etchegoin 

formation

UpP«

part

1058

F

R R

F

F

R,

R

R,

R,

R,

R,

F

Lower part

1117 1060

R

R
PLIOCENE DIATOMS FROM THE KETTLEMAN HILLS, CALIFORNIA

Pliocene diatoms from Kettleman Hills, Calif.—Continued

85

Nitzschia tryblionella Hantzsch var. maxima Grunow _ ___ __ _

tryblionella var. victoriae Grunow ____ _ ___

etchegoinia Hanna and Grant (pi. 23, fig. 12) _ _

navicularis Grunow (pi. 22, fig. 11) _________ _ _ _

punctata (W. Smith) Grunow (pi. 23, fig. 11) _____ _ _ __

granulata Grunow (pi. 22, fig. 10) _ ___ ____ __

cf. N. denticula Grunow. _ _ _ _ _ __

scalaris (Ehrenberg) W. Smith _ ___ _______

Cymatopleura sp____ ________ ____ _ ______

utahensis Grunow (pi. 23, fig. 1) __________

Ca mpylodiscus echeneis Ehrenberg _ ____ _______

clypeus Ehrenberg- __ __________

Tulaie formation

1061

F

839 838

F

K

F

R 

R

R

1053

F 

F

C

C

R

F 

F 

F 

R

San Joaquin formation

Tuflaceous 

sandstone

1054

R

F

1056

F

F

1057

F

Necerita 

zone

1052

R

1051

F

R

R

Etchefoin 

formation

Upper 

part

1058

R,

R

F

Lover part

1117

———

1060

R

STRATIGRAPHY AND DIATOM FLORAS

ETCHEGOIN FORMATION

The name "Etchegoin beds" was first used by F. M. 

Anderson 1 for 2,500 to 4,000 feet of sand, gravel, and 

clay exposed near the Etchegoin ranch, about 20 miles 

northeast of Coalinga, in the NW/4 sec. 1, T. 19 S., 

R. 15 E., Mount Diablo base and meridian, Fresno 

County. He divided his Etchegoin beds into a lower 

part, called the "Etchegoin sands", consisting of 1,200 

to 2,500 feet of unconsolidated sand and gravel, and 

an upper part, called the "San Joaquin clays", consisting of 1,500 feet of sandstone and shale.

Arnold and Anderson 2 usqd the name "Etchegoin 

formation" to include both the Etchegoin sands and 

the San Joaquin clay of F. M. Anderson and applied 

the name to the beds in the Kettleman Hills under 

discussion in the present paper.

Woodring and Stewart 3 have used the name "Etchegoin formation" for the lower part of the Etchegoin of 

Arnold and Anderson in Bulletin 398, and that is the 

usage followed here.

The Etchegoin is dominantly sandstone, with some 

shale in the upper part, and contains the oldest rocks 

exposed in the Kettleman Hills. A marine diatom 

flora of 57 species and varieties was obtained from this 

formation, the most characteristic and abundant of 

which are shown in plate 20.

LOWER PART OF ETCHEGOIN FORMATION

U. S. G. S. diatom locality 1060. East flank of South Dome, 

Kettleman Hills, Kings County, Calif. 1,700 feet north of 

southeast corner sec. 34, T. 24 S., R. 19 E., Mount Diablo base

1 Anderson, F. M., A stratigraphic study in the Mount Diablo Range of California: 

California Acad. Sci. Proo., 3d ser., vol. 2, pp. 178-192, 1905.

2 Arnold, Ralph, and Anderson, Robert, Preliminary report on the Coalinga oil 

district: U. S. Geol. Survey Bull. 357, pp. 46-55, 1908; Geology and oil resources of 

the Coalinga district, Calif.: U. S. Geol. Survey Bull. 398, pp. 113-140, 1910.

s Woodring, W. P., Stewart, Ralph, and Richards, R. W., Geologic map of the 

Kettleman Hills, California (advance ed.), U. S. Geol. Survey, 1934.

and meridian. Estimated to be 1,500 feet stratigraphically 

below the top of the Etchegoin formation. Pliocene. Co^ected 

by W. P. Woodring, December 17, 1931.

A marine diatom flora of 29 species and varieties was 

obtained from this locality. (See table.) The freshwater species—such as Melosira solida var. haitiensis, 

M. granulata, M. granulata var. curvata, Epithemia 

turgida, and Nitzschia granulata—occur only rarely 

and, furthermore, are species which, while preferring 

fresh water, also inhabit brackish water. It is quite 

probable that these fresh-water forms were carried into 

the basin of deposition by streams. The occurrence of 

large numbers of distinctly pelagic marine genera, such 

as Stephanopyxis, Coscinodiscus, Chaetoceros, Periptera, 

Syndendrium, Dicladia, Omphalotheca, Xanthiopyxis and 

Thalassionema, suggests deposition from fairly open 

water.

Several fragments of a Lithodesmium in this sample 

are referred to L. cornigerum Brun,4 a common ertinct 

species in the Pliocene diatomite in the Casmalia Hills 

and Solomon Hills 5 bordering the Santa Maria Valley, 

Santa Barbara County, Calif. Other species common 

to the two localities are Coscinodiscus oculus-iridis, 

C. suUilis, and Actinoptychus undulatus. These, however, are species that range from Miocene to Recent 

and hence are not so significant.

Lithodesmium cornigerum has been found so far only 

in Pliocene rocks in California. Hanna 6 has found the 

species in a core sample taken from a depth of 800- 

1,000 feet in the H. B. Porter well no. 1, sec. 2% T. 

28 S., R. 21 E. Mount Diablo meridian, Kern County, 

Calif., and says: "This material came from a stratum 

of diatomite which had well-preserved and definitely

« Bran, J., Le diatomiste, vol. 2, p. 239, pi. 24, figs. 15, 16,17,1896.

5 Arnold, Ralph, and Anderson, Robert, Geology and oil resources of tin Santa 

Maria oil district, Santa Barbara County, Calif.: U. S. Geol. Survey Bull. 322, p. 41, 

pi. 10, fig. 16,1907.

6 Hanna, G. D., Observations on Lithodesmium cornigerum Brun: Jour. Paleontology, vol. 4, pp. 189-191, pi. 14, figs. 9,10, 1930.
86 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1937

identified Etchegoin Pliocene molluscan fossils, both 

above and below."

The most abundant species found in the lower part 

of the Etchegoin formation are Coscinodiscus excentricus 

(pi. 20, fig. 5), C. asteromphalus, C. asteromphalus var. 

omphalantha (pi. 20, fig. 2), C. kurzii (pi. 20, fig. 1), 

Adinoptychus undulatus (pi. 20, fig. 8), Actinocyclus 

ehrenbergii (pi. 22, fig. 1), and Xanthiopyxis ovalis (pi. 

20, fig. 6). Although the last-named species is abundant in the lower part of the Etchegoin formation, 

occurs frequently to commonly in the San Joaquin 

formation, and rarely even in the lower part of the 

Tulare formation, it was not found in the upper part 

of the Etchegoin formation (locality 1058). Its great 

abundance in the lower part and complete absence in 

the upper part makes it appear to be a characteristic 

species for the lower Etchegoin formation, at least so 

far as was indicated by the collections studied for this 

report.

U. S. G. S. diatom locality 1117. North Dome, Kettleman 

Hills, Fresno County, Calif., 3,100 feet east and 3,280 feet north 

from southwest corner of sec. 12, T. 22 S., R. 17 E., Mount 

Diablo base and meridian, 60 feet stratigraphically below the 

base of the Macoma zone, upper part of the Etchegoin formation. Pliocene. Collected by Ralph Stewart, 1931.

All the diatoms present in this sample (see table) 

were badly corroded, suggesting leaching by alkaline 

solutions. The three species found are among the 

diatoms having relatively thick tests, and it is safe to 

assume that a large number of species were present 

before the leaching took place, and that the more 

delicate forms have been removed altogether. The 

three species range from Miocene to Recent and indicate little else than marine deposition.

UPPER PART OF ETCHEGOIN FORMATION

U. S. G. S. diatom locality 1058. West flank of South Dome, 

Kettleman Hills, Kings County, Calif., 1,620 feet north and 

330 feet east from southeast corner of sec. 11, T. 25 S., R. 19 E., 

Mount Diablo base and meridian. About 125 feet stratigraphically below base of San Joaquin formation. Etchegoin formation, Pliocene. Collected by W. P. Woodring, October 10, 1931.

This sample yielded 42 species and varieties of 

diatoms (see table), some of the more abundant and 

characteristic of which are illustrated in plate 20. 

This diatom assemblage strongly indicates deposition 

under marine conditions. Thirteen fresh-water and 

brackish-water species at first sight suggest brackish 

water, but only two, Stephanodiscus dubius and 

Nitzschia granulata, occur in amounts greater than rare. 

It appears reasonable, therefore, to explain their 

presence on the probability of their introduction into 

the basin of deposition by streams. Stephanodiscus 

dubius (pi. 20, fig. 10) is now living in lakes and slowly 

moving rivers, and its presence here in fair amounts 

suggests a river emptying into the basin somewhere 

nearby. It is also present in the Tulare formation 

(locality 838) in about the same relative abundance.

A very interesting diatom present in rare amounts is 

Melosira solida var. multiformis, originally described 

from Miocene nonmarine beds in Patagonia by Frenguelli, 7 who figured forms that are circular, oval, and 

roundly quadrangular in valve view. Only the oval 

form was found in the Kettleman Hills. I have also 

found it occurring abundantly in a fresh-water diatomite 

of supposed Miocene age near Drewscy, Harney 

County, Oreg. Nitzschia etchegoinia (pi. 23, fig. 12), 

originally described by Hanna and Grant 8 from 

brackish-water beds on the north end of North Dome, 

Kettleman Hills, occurs here only rarely and represents 

the earliest known occurrence of this diatom. The 

species was originally described from bed^1 now considered to belong to the Tulare formation.

This assemblage is characterized by an abundance 

of Coscinodiscus excentricus (pi. 20, fig. £), C. asteromphalus var. omphalantha (pi. 20, fig. 2), C. kurzii (pi. 

20, fig. 1), and Actinoptychus undulatus (pi. STO, fig. 8), all 

of which range from Miocene to Recent. T1 «- following 

species were found to be limited to the uppe*1 part of the 

Etchegoin formation in the Kettleman Hil\ although 

many of them have longer ranges elsewhere. Endictya 

robusta (pi. 20, fig. 4), a common species in the upper Miocene in California, occurs frequently. Its known range is 

Miocene to Recent. Coscinodiscus vetustissimus (pi. 20, 

fig. 7) is a very distinctive species characteristic of the 

upper part of the Etchegoin formation. It was 

originally described by Pantocsek 9 from marine 

Tertiary beds in Hungary. The only specks found in 

the Kettleman Hills with which it may be confused is 

Coscinodiscus cirrus (pi. 21, fig. 4), and the differences 

between the two are ^iscussed under the original 

description of that species on page 91 of this report. 

Its known range is from Oligocene (?) to Recent. The 

occurrence of Coscinodiscus inclusus (pi. 20, fig. 3) 

in the upper part of the Etchegoin formation is particularly interesting, as it marks the upper limit for the 

known range of this diatom. It was originaJly described 

by Rattray 10 from an unnamed figure in Schmidt's 

Atlas. 11 The original material came from "Richmond, 

Virginia," presumably from the diatomite in the 

Calvert formation, of middle Miocene age, which crops 

out in that city. No other occurrence of tins species is 

known. The short form only of Rhaphoneis angularis 

(pi. 22, fig. 8; see original description, pp. S2-93 of this 

report) was found frequently in the upper part of the 

Etchegoin formation. In the collections studied for 

this report this species was found only in the San Joa-

' Frenguelli, Gioacchino, Tecamebiani e diatomee nel Miocene del Neuqufin 

(Patagonia settentrionale): Soc. geol. italiana Boll., vol. 52, pp. 40-42, pi. 5, figs. 8-16, 

text fig. on p. 41,1933.

8 Hanna, G. D., and Grant, W. M., Brackish-water Pliocene diatoms from the 

Etchegoia formation of central California: Jeur. Paleontology, vol. 3, p. 99, pi. 14, 

fig. 3, 1929.

9 Pantocsek, Josef, BeitrSge zur Kenntniss der fossilen Bacillarien Ungarns, I, 

p. 71, pi. 20, fig. 186, 1886.

"> Eattray, John, A revision of the genus Coscinodiscus and s?me allied genera: 

Royal Soc. Edinburgh Proc., vol. 16, p. 482,1889.

» Schmidt, Adolf. Atlas der Diatomaceenkunde, pi. 57, fig. 47, 1878.
PLIOCENE DIATOMS FROM THE KETTLEMAN HILLS, CALIFORNIA 87

quin formation and the upper part of the Etchegoin 

formation. The elongate forms (pi. 22, figs. 6 and 7) 

were found only in the San Joaquin formation. Navicula clavata var. elliptica (pi. 20, fig. 9) 12 is a tropical 

form first reported from Samoa and differs from N, 

clavata Gregory only in not having rostrate apices. 

It is reported as rare in the accompanying table, 

although several fragments which probably belong to 

this variety were found. The only Lithodesmium 

found was a very small undetermined species not at all 

to be confused with L. cornigerum.

SAN JOAQUIN FORMATION

The name "San Joaquin clay" was first used by F. M. 

Anderson 13 for the upper part of the Etchegoin formation. Arnold and Robert Anderson included the beds 

now called the San Joaquin formation in the Etchegoin 

in Bulletin 398, without special designation.

Barbat and Galloway 14 described the beds, raised 

the San Joaquin clay to formation rank and named the 

North Dome of Kettleman Hills as the type locality. 

They assigned over three-quarters of the formation to 

the Pleistocene and the remainder to the Pliocene.

Woodring and Stewart 15 have used the term "San 

Joaquin formation" to include the upper part of the 

Etchegoin of Arnold and Anderson and have assigned 

it all to the Pliocene. They have divided the formation 

into several faunal zones, a detailed description of which 

is given in their report now in preparation. Diatoms 

were obtained from two localities in the Neverita zone 

and from three localities in an overlying tuffaceous 

sandstone.

NEVERITA ZONE

U. S. G. S. diatom locality 1051. East side of Middle Dome, 

Kettleman Hills, Kings County, Calif., 1,650 feet south and 

2,100 feet west from northeast corner of sec. 33, T. 23 S., R. 19 E., 

Mount Diablo base and meridian. Rodent debris at locality 

corresponding to a stratigraphic position about 25 feet above 

base of Neverita zone, San Joaquin formation, Pliocene. Collected by W. P. Woodring, May 30, 1932.

U. S. G. S. diatom locality 1052. West side of Middle Dome, 

Kettleman Hills, Kings County, Calif., 570 feet south and 1,850 

feet west from northeast corner of sec. 8, T. 24 S., R. 19 E., 

Mount Diablo base and meridian. Rodent debris at locality 

corresponding essentially to same horizon as locality 1051. 

Neverita zone, San Joaquin formation, Pliocene. Collected by 

W. P. Woodring, May 31, 1932.

Material from these two localities yielded, as might 

be expected, very similar diatom assemblages, but with 

several noteworthy differences. Out of a total of 56 

species and varieties from the two localities, 21, or 37 

percent, were common to both. If the species reported 

as rare are eliminated, 66 percent are common to the

12 Schmidt, Adolf, op. cit., pi. 3, fig. 13.

13 Anderson, F. M., A stratigraphic study in the Mount Diablo Range of California: 

California Acad. Sci. Proc., 3d ser., vol. 2, pp. 178-192, 1905.

14 Barbat, W. F., and Galloway, John, San Joaquin clay, California: Am. Assoc. 

Petroleum Geologists Bull., vol. 18, no. 4, pp. 476-499,1934.

16 Woodring, W. P., Stewart, Ralph, and Richards, R. W., Geologic map of the 

Kettleman Hills, California (advance ed.), U. S. Geol. Survey, 1934.

150226—38——2

two localities. The diatom floras from the Neverita 

zone are dominantly marine and are characterized by 

Melosira sulcata (pi. 22, fig. 15), Stephanopyxis corona 

(pi. 22, fig. 2), Coscinodiscus excentricus (pi. 21, f 7. 5), 

C. subtilis (pi. 21, fig. 6), C. cirrus, n. sp. (p. 90, pi. 21, 

fig. 4), C. obscurus (pi. 21, fig. 1), C. asteromphalus 

(pi. 21, fig. 3), C. asteromphalus var. omphalantha 

(pi. 20, fig. 2), C. kurzii (pi. 21, fig. 2), Actinoptychus 

undulatus (pi. 22, fig. 3), Actinocyclus ehrenbergii (pi. 22, 

fig. 1), A. subtilis, and Xanthiopyxis ovalis, n. sp. (p. 91, 

pi. 22, fig. 12). Most of the forms are pelagic, suggesting fairly open water at the time of deposition.

Several species inhabiting only fresh and brr,ckish 

waters are present, usually in rare amounts, Hit it 

seems reasonable to assume that they were introduced 

by streams, as the assemblage is overwhelmingly marine 

in character.

Melosira recedens (pi. 22, figs. 13, 14) was found, only 

in the San Joaquin formation in the Kettleman Hills. 

It was found more abundantly in the overlying tuffaceous sandstone than in the Neverita zone. This species 

was first described 16 from the Eocene "Cementrtein" 

on the island of Mors, Jutland. Heretofore it has been 

recorded only from the type locality, and this Pliocene 

occurrence in the Kettleman Hills marks the upper 

limit of its known geologic range. Coscinodiscus cirrus, 

n. sp. (pi. 21, fig. 4; see original description on p. 90 of 

this report) is one of the most distinctive species found 

in the collections studied. It occurs commonly in both 

collections from the Neverita zone and frequently in one 

collection (locality 1056) from the overlying tuffaceous 

sandstone, but at no other locality. It appears to be 

one of the most characteristic diatoms in the Neverita 

zone and can usually be found in a strewn slide of diatoms from the localities mentioned. It can be distinguished immediately by the small excentric circlet of 

enlarged areolae. The genus Aulacodiscus was found 

only in this zone, represented by many fragments 

assigned to A. cf. A. argus and one good valve of A. 

brownei. Biddulphia aurita, which ranges from Miocene to Recent, was found frequently in both collections 

from this zone but at no other locality in the Kettleman 

Hills. Hemidiscus ovalis, n. sp. (pi. 22, fig. 9; see 

original description, p. 91) was found only at locality 

1052 in this zone and at two localities (1056 and 1057) 

in the overlying sandstone. In the collections studied, 

this species is limited to the San Joaquin formation. 

A closely related species, H. margaritaceus, 17 was described from rocks of supposed Pliocene age in Japan. 

Both the long and short forms of Rhaphoneis angrlaris, 

n. sp. (pi. 22, figs. 6, 7, and 8; see original description, 

p. 92) were found frequently in both collections from 

this zone and in one collection (locality 1054) from the 

overlying tuffaceous sandstone. The long forms (pi. 22,

16 Schmidt, Adolf, Atlas der Diatomaceenkunde, pi. 176, fig. 54; pi. 177, figs. 62-64, 

1892.

« Brun, J., and Tempere, J., DiatomSes fossiles du Japon: Soc. phys. et hist. nat. 

Geneve Mto., tome 30, no. 9, p. 37, pi. 4, fig. 6a, 1889.
SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1937

figs. 6 and 7) were found only in the San Joaquin formation. Navicula pennata (pi. 22, fig. 16) was fairly uniformly distributed through all five of the collections 

from the San Joaquin formation and in no others. Its 

known range is "Tertiary" 18 to Recent. 19

TUFFACBOUS SANDSTONE OVERLYING NEVERITA ZONE

U. S. G. S. diatom locality 1054. West side of North Dome, 

Kettleman Hills, Fresno County, Calif., 1,500 feet north and 

1,230 feet east from southwest corner of sec. 3, T. 22 S., R. 17 E., 

Mount Diablo base and meridian. Tuffaceous sandstone about 

125 feet stratigraphically above base of Neverita zone, San 

Joaquin formation, Pliocene. Collected by W. P. Woodring, 

June 22, 1932.

U. S. G. S. diatom locality 1056. East flank of North Dome, 

Kettleman Hills, Kings County, Calif., cut on south side of 

Cottonwood Pass road, 1,430 feet south and 80 feet east from 

northwest corner of sec. 6, T. 23 S., R. 19 E., Mount Diablo base 

and meridian. Tuffaceous sandstone about 125 feet stratigraphically above base of Neverita zone, San Joaquin formation, 

Pliocene. Collected by W. P. Woodring, September 30, 1931.

U. S. G. S. diatom locality 1057. East flank of North Dome, 

Kettleman Hills, Kings County, Calif. Same locality as 1056. 

Silty clay about 20 feet lower stratigraphically. Tuffaceous sandstone and clay overlying Neverita zone, San Joaquin formation, 

Pliocene. Collected by W. P. Woodring, September 30, 1931.

A marine diatom assemblage of 78 species and varieties was obtained from the three localities in the tuffaceous sandstone and associated clay. This assemblage 

indicates deposition under marine conditions and is 

characterized by Melosira sulcata (pi. 22, fig. 15), 

M. recedens (pi. 22, figs. 13, 14), Stephanopyxis corona 

(pi. 22, fig. 2), Coscinodiscus subtilis (pi. 21, fig. 6), 

C. cirrus (pi. 21, fig. 4), C. obscurus (pi. 21, fig. 1), 

C. radiatus, C. kurzii (pi. 21, fig. 2), Actinoptychus 

undulatus (pi. 20, fig. 8; pi. 22, fig. 3), Actinocyclus 

ehrenbergii (pi. 22, fig. 1), Omphalotheca sp., Xanthiopyxis ovalis (pi. 20, fig. 6; pi. 22, fig. 12), Hemidiscus 

ovalis (pi. 22, fig. 9), Bhaphoneis angularis (pi. 22, figs. 

6-8), R.Jatula (pi. 22, fig. 5), Navicula pennata (pi. 22, 

fig. 16), and Nitzschia granulata (pi. 22, fig. 10).

Many pelagic genera are present in this assemblage, such as Stephanopyxis, Thalassiosira, Coscinodiscus, Rhizosolenia, Bacteriastrum, Omphalotheca, Stephanogonia, Xanthiopyxis, and Thalassionema.

Melosira recedens (pi. 22, figs. 13, 14) was found in 

the samples from the tuffaceous sandstone much more 

abundantly than in the, underlying Neverita zone. 

It was not found in the sample from locality 1054. 

The known geologic range of this species is Eocene to 

Pliocene. Coscinodiscus cirrus (pi. 21, fig. 4) was 

found in only one sample (locality 1056) in the tuffaceous sandstone, although it is one of the most characteristic and abundant forms found in the Neverita 

zone. It is known only from the San Joaquin formation. Coscinodiscus oculus-iridis, which has a known 

range from Eocene to Recent, occurs more abundantly

is Pantocsek, Joseph, Beitrage zur Kenntniss der fossilen Bacillarien Ungarns, I, 

p. 28, 1886. 

» Schmidt, Adolf, Atlas der Diatomaceenkunde, pi. 48, figs. 41-43, 1876.

in the tuffaceous sandstone than in other parts of the 

section in the Kettleman Hills. Coscinodiscus asteromphalus (pi. 21, fig. 3) was found in much fev^er numbers 

than in the Neverita zone, although the variety omphalantha is common in the tuffaceous sandstone but absent 

in both samples from the Neverita zone. Hemidiscus 

ovalis occurs much more abundantly in tin tuffaceous 

sand than in the Neverita zone. It is known only 

from the San Joaquin formation. RhapKoneis Jatula 

(pi. 22, fig. 5) appears to be one of the most distinctive 

species in the tuffaceous sandstone, where it was found 

commonly in two collections (localities 1056 and 1057) 

out of the three studied. It occurred in ro other collection from the Kettleman Hills. This species bears 

a superficial resemblance to R. parilis Hsnna,30 originally described from the Temblor formation near 

Sharktooth Hill, Kern County, Calif. Th^ differences 

between the two are discussed in the original description of R.Jatula on pages 93-94 of this report. Navicula 

pennata (pi. 22, fig. 16) is another distinctive species 

found in all collections from the San Joaquin and in no 

other sample from the Kettleman Hills.

TUIARE FORMATION

The Tulare formation was originally proposed by 

F. M. Anderson 21 for the beds overlying his San 

Joaquin clay in the Kettleman Hills along the western 

border of the former Tulare Lake. He assigned it 

doubtfully to the Pliocene. Arnold and Anderson 22 

gave a discussion of its occurrence, lithology, and 

characteristic fossils and assigned it to upper Pliocene 

and lower Pleistocene. They gave a maximum thickness of 3,100 feet in what is now called the Middle 

Dome, consisting of gravel, gypsiferous sand, and clay. 

At the present time the Tulare formation i^1 assigned to 

the Pliocene and Pleistocene (?).

On the basis of the collections studied fo1* this report, 

the Tulare formation exceeds all others in the Kettleman Hills in the diversity of its diatom floras. Four 

collections from the Tulare formation yielded a total of 

136 species and varieties of diatoms, of which only 26, 

or 19 percent, occur in the Etchegoin and San Joaquin 

formations. This abrupt change is due to the fact 

that the diatom floras in the two older formations were 

marine, whereas those in the Tulare formation were 

deposited in brackish and fresh water. The most 

characteristic and abundant Tulare diatoms are shown 

in plate 23.

The four collections fall into two groups—(1) 838, 

839, and 1053, from three different geographic localities 

in the North Dome, in a bed of white clay that occurs 

at the base of the Tulare formation and (2) 1061, in the

2° Hanna, G. D., The diatoms of Sharktooth Hill, Kern County, Calif.: California 

Acad. Sci. Proc., 4th ser., vol. 20, no. 6, p. 214, pi. 16, figs. 2, 3, 4, 1932.

21 Anderson, F. M., A stratigraphic study in the Mount D'ablo Range, Calif.: 

California Acad. Sci. Proc., 3d ser., vol. 2, p. 181,1905.

22 Arnold, Ralph, and Anderson, Eobert, Geology and oil resorrces of the Coalinga 

district, Calif.: U. S. Geol. Survey Bull. 398, pp. 140-154,1910.
PLIOCENE DIATOMS FROM THE KETTLEMAN HILLS, CALIFORNIA 89

Middle Dome from the lower Amnicola zone, about 180 

feet above the base of the Tulare formation.

U. S. G. S. diatom locality 838. North end of North Dome, 

Kettleman Hills, Fresno County, Calif., 2,340 feet east of northwest corner of sec. 35, T. 21 S., R. 17 E., Mount Diablo base and 

meridian. White clay at base of Tulare formation, Pliocene. 

Collected by W. P. Woodring and K. E. Lohman, December 2, 

1930.

This collection yielded a diatom flora of 91 species 

and varieties representing deposition in fresh or slightly 

brackish water. The most abundant and characteristic 

diatoms are Melosira granulata (pi. 23, fig. 8), M. 

ambigua (pi. 23, fig. 9), Stephanodiscus carconensis (pi. 

23, fig. 2), and S. carconensis var. pusiila. Other 

species, less abundant but characteristic of the flora, 

are Eunotia robusta var. tetraodon (pi. 23, fig. 6), E. 

serpentina, Cymbella prostrata (pi. 23, fig. 15), Navicula 

peregrina, and Nitzschia punctata (pi. 23, fig. 11). 

This locality yielded the most diverse diatom flora 

found in the Kettleman Hills, including a large number 

of species that occurred in none of the other collections.

Stephanodiscus carconensis (pi. 23, fig. 2) has been 

found in fresh-water lake beds of supposed Pliocene age 

in Oregon and has not been reported living. Cyclotella 

iris is an extinct species, first described 23 from upper 

Pliocene fresh-water lake beds in Auxillac, Cantal, 

France, and has not been found before in North 

America. Cyclotella pygmaea, another extinct species, 

was first described 24 from an andesitic tuff deposited in 

a fresh-water lake bed of Sarmatian age in Szliacs, 

Hungary. Pantocsek's original figure, cited above, is 

very poor. He subsequently published two better 

figures,25 which should be used for comparison with the 

Kettleman Hills form. Diploneis smithii (pi. 23, fig. 10) 

occurred frequently at locality 838 but was much more 

abundant at locality 1053. At present this species 

usually lives in a brackish- to salt-water environment, 

although it has been found in a few fresh-water lakes in 

Germany. Nitzschia punctata (pi. 23, fig. 11) is another 

brackish-water species found frequently at locality 838 

but in no other sample from the Kettleman Hills. 

Although many species inhabiting both fresh and brackish waters are present, and a much smaller number that 

are usually found only in brackish waters, only one 

typically marine species, Coscinodiscus kutzingii, was 

found, and that only rarely. The diatom flora as a 

whole is dominantly of fresh-water habitat, with a 

brackish-water influence present, such as might be 

found in a nearly land-locked basin slightly above tide 

level.

U. S. G. S. diatom locality 839. East side of North Dome, 

Kettleman Hills, Fresno County, Calif., 980 feet north and 

730 feet west from southeast corner of sec. 20, T. 21 S., R. 17 E.,

23 Heribaud, Joseph, Les diatomees d'Auvergne, p. 224, pi. 6, figs. 1-4,1893.

24 Pantocsek, Josef, Beschreibung und Abbildung der fossilen Bacillarien des 

Andesittufles von Szliacs in Ungarn, p. 17, pi. 2, fig. 67,1903.

25 Pantocsek, Josef, Beitrage zur Kenntniss der fossilen Bacillarien Ungarns, III, 

p. 37, pi. 2, fig. 22; pi. 4, fig. 59, 1905.

Mount Diablo base and meridian. White clay at base of Tulare 

formation, Pliocene. Collected by W. P. Woodring and K. E. 

Lohman, December 2, 1930.

This collection yielded a large number of dia.toms 

which were so badly corroded that only 6 species could 

be identified. The corrosion suggests leaching by 

alkaline solutions. The few species identified indicate 

ecologic conditions similar to those at locality 838.

U. S. G. S. diatom locality 1053. East side of North Dome, 

Kettleman Hills, Kings County, Calif., 1,040 feet south and 

2,760 feet east from northwest corner of sec. 25, T. 22 S., R. 18 E., 

Mount Diablo base and meridian. White clay at base of Tulare 

formation, Pliocene. Collected by W. P. Woodring, June 18, 

1932.

This collection yielded a diatom flora of 56 sp ^cies 

and varieties, which include 13 out of the 16 species 

recorded by Hanna and Grant 2a from what is proH,bly 

the same bed. The most characteristic specier are 

Melosira granulata (pi. 23, fig. 8), Hyalodiscus schmidtii 

(pi. 23, fig. 5), Cyclotella meneghiniana, Diploneis 

smithii (pi. 23, fig. 10), Navicula marina (pi. 23, fig. 13), 

Cymbella mexicana (pi. 23, fig. 14), Nitzschia etchegnnia 

(pi. 23, fig. 12), N. granulata (pi. 22, fig. 10), Surirella 

striatula, and S. utahensis (pi. 23, fig. 1).

The occurrence of large numbers of such marine 

species as Melosira sulcata, M. sol, Podosira stelliger, 

Thalassiosira decipiens, Coscinodiscus excentricus, Actinoptychus undulatus,Xanthiopyxis ovalis,axid Tricerctium 

uncinatum, together with such brackish-water and 

marine species as Hyalodiscus schmidtii, Terp«inoe 

americana, Diploneis smithii, Navicula marina, Campylodiscus echeneis, and C. clypeus strongly indicates 

brackish-water conditions during deposition.

The large number of fresh-water and fresh- and brackish-water species suggests that truly marine conditions 

did not prevail, but rather that deposition took place 

at or near tide level, where a mixing of fresh-water, 

brackish-water, and marine forms would occur.

An extinct variety found rarely in this collection, 

Cyclotella compta var. pliocaenica, was originally 

described 27 from an upper Pliocene clay near Willerhausen, South Hanover, Germany, in which bones of 

Mastodon arvernense were also found. Xanthiopyxis 

ovalis (pi. 22, fig. 12) was found in the Tulare formr.tion 

in this collection only, although it occurs much more 

commonly in both the San Joaquin and Etchegoin 

formations. Nitzschia etchegoinia (pi. 23, fig. 12), 

which was originally described ?8 from what is probably 

the same bed as that represented at locality 1053, is a 

very distinctive and common species in this locality. 

It was found, and then rarely, in only one other sample 

(from locality 1058, in the Etchegoin formation) among 

the collections studied from the Kettleman Hills.

26 Hanna, Q. D., and Grant, W. M., Brackish-water diatoms from the Etchegoin 

formation of central California: Jour. Paleontology, vol. 3, no. 1, pp. 87-100, pi 11-14, 

1929.

s'Krasske, Qeorg, Diatomeen aus dem OberpHocan von Willerhausen: Archiv fiir 

Hydrobiologie, Band 24, Heft 3, p. 435, pi. 16, figs. 1-6, Berlin, 1932.

« Hanna, Q. D., and Grant, W. M., op. cit., p. 99, pi. 14, fig. 3.
90 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1937

Although the collections from the three localities 

(838, 839, and 1053) described above were obtained 

from the same 12-foot bed of white clay at the base 

of the Tulare formation at different points along the 

strike, the diatom flora obtained at locality 1053 is 

quite different from those obtained at localities 838 and 

839. The diatoms from locality 839 were so badly 

leached that the flora is very incomplete and hence is 

left out of the present discussion. The diatom floras 

from the other two localities show a definite change 

from fresh-water conditions at locality 838 to brackishwater conditions at locality 1053. The exact position 

in the 12-foot bed of these two collections is not known, 

so it is not possible to state whether the change in the 

floras represents an increase or decrease in salinity for 

the tune represented by the deposition of this bed. As 

the collections were made at points some distance apart, 

it is possible that different ecologic conditions were 

present in different parts of the basin at the same tune 

or at slightly different tunes. During the summer of 

1934 I collected a suite of 26 samples at 6-inch intervals 

from bottom to top of this bed at locality 838. A 

study of this material may provide an answer to the 

question of the changing ecologic conditions during this 

part of early Tulare time at this locality. I have had 

no opportunity as yet to make this study but hope to 

do so in the near future.

U. S. G. S. diatom locality 1061. East flank of Middle Dome, 

Kettleman Hills, Kings County, Calif., arroyo along old DudleyLemoore road, 1,690 feet south and 1,870 feet east from northwest corner of sec. 17, T. 23 S., R. 19 E., Mount Diablo base and 

meridian. Lower Amnicola zone, about 180 feet stratigraphically above the base of the Tulare formation, Pliocene. Collected by W. P. Woodring, December 17, 1931.

This collection yielded a diatom flora of 16 species 

and varieties, of which three—Stephanopyxis turris var. 

cylindrus, Cocconeis scutellum var. minutissima, and 

Diploneis advena—are marine, and the rest now live in 

fresh or brackish waters. The most characteristic forms 

are Epithemia zebra, particularly the variety saxonica 

(pi. 23, fig. 3), Rhopalodia gibba (pi. 23, fig. 4) and the 

variety ventricosa, Melosira granulata (pi. 23, fig. 8), and 

Mastoglow elliptica. These forms suggest deposition in 

fresh to brackish water of lower salinity than that 

indicated by the diatom flora from locality 1053.

One extinct variety, Navicula pennata var. kinkeri, 

first described by Pantocsek 29 from "Tertiary" marl in 

Szdkal, Hungary, and also known from the Calvert 

formation (middle Miocene) exposed near Petersburg, 

Va., was found rarely in this collection. Whether this 

variety was living in Tulare time or was redeposited 

from Miocene diatom-bearing rocks then being eroded 

cannot be determined. Arnold and Anderson 30 recorded the occurrence in the lower part of the Tulare 

formation of angular fragments of hard white siliceous 

shale, derived presumably from their Tejon or Santa

» Pantocsek, Josef, Beitrage zur Kenntnis der fossllen Bacillarien Ungarns, II, 

p. 49, pi. 9, fig. 169, 1889. 

s« Arnold, Ralph, and Anderson, Robert, U. S. Geol. Survey Bull. 398, p. 145,1910.

Margarita (?) formations. (The upper part of the 

Tejon formation of Arnold and Anderson is now assigned 

to the Kreyenhagen shale; their Santa Margarita (?) 

formation is designated the McLure stale.) Reef 

Ridge, southwest of Kettleman Hills, is tho most probable source of the angular fragments of siliceous shale 

from the Kreyenhagen and the McLure shr.les recorded 

by Arnold and Anderson. I have obtained well-preserved diatoms from hard calcareous concretions in the 

McLure shale on Reef Ridge, but preserved diatoms 

have not been obtained from either the McLure or the 

Kreyenhagen shale in this region. Good impressions of 

diatoms have been seen in both, but the ehales are so 

highly silicified that none of the original material of the 

diatoms is present, and their positive determination is 

impossible. Arnold and Anderson 3I also reported the 

occurrence of porcelain shale in the Etchego^n formation 

in the Kettleman Hills, which indicates that the silicification of the shales mentioned above took place before 

Tulare time. It thus appears extremely unlikely that 

the diatom mentioned above could have l^,en derived 

from either the Kreyenhagen or the McLure shale.

DESCRIPTIONS OF NEW SPECIE''

ALGAE 

Class DIATOMAGEAE

Order CENTRALES

Suborder DISCINEAE

Family COSCINODISCACEAE

Subfamily GOSGINODISGOIDEAE

Genus COSCINODISCUS Ehrenberg:

Coscinodiscus cirrus Lohman, n. sp

Plate 21, figure 4

Valve circular, slightly convex, especially near the 

margin. Areolae hexagonal, arranged in curved rows, 

subfasciculate, 5 to 6 in 0.01 mm at half the radius, 6 to 

7 in 0.01 mm near the center and 11 to 12 in 0.01 mm 

very near the margin. Central papillae large but very 

faint and clearly visible only when mounted in medium 

of high refractive index. No central spac°, or rosette. 

A ring of areolae slightly larger than those adjacent 

form a circle 0.010 to 0.013 mm in diameter and about 

one-seventh of the radius from the center of the valve; 

markings converge to its center. Secondary curved 

oblique decussating rows evident, especiall^ in the central portion. Margin narrow, bearing short radial 

striae, 12 to 13 in 0.01 mm. Larger areolae occur just 

within the margin and 0.006 to 0?007 mm apart. 

Diameter of valve 0.10 to 0.13 mm.

Diameter of figured specimen 0.121 mm.

Holotype: No. 1630-1, U. S. G. S. diatom collection. 

CoUected by W. P. Woodring May 31, 1932, from 

rodent debris at locality corresponding to stratigraphic 

position about 25 feet above base of Neverita zone, 570 

feet south and 1,850 feet west from northeast corner of 

sec. 8, T. 24 S., R. 19 E., Mount Dial T o base and

si Idem, p. 123.
PLIOCENE DIATOMS FROM THE KETTLEMAN HILLS, CALIFORNIA 91

meridian, west side of Middle Dome, Kettleman Hills, 

Kings County, Calif., U. S. G. S. diatom locality 1052. 

Neverita zone, San Joaquin formation, Pliocene.

This species bears a superficial resemblance to 

Coscinodiscus subtilis Ehrenberg as figured in Schmidt's 

Atlas, plate 57, figures 13 and 14. The following consistent differences serve to distinguish the two: 

C. subtilis C. cirrus

Areolae always in straight 

rows.

Areolae forming definite fasciculi with rows parallel to 

central radial row in each 

fasciculus.

Ring (when present) concentric.

Areolae always in curved 

rows.

Areolae forming indefinite fasciculi with rows concentric 

to one marginal row in each 

fasciculus.

Ring always present and always excentric.

C. vetustissimus (pi. 20, fig. 7), a frequent species in 

the Etchegoin formation, bears a superficial resemblance 

to C. cirrus, especially under very low magnifications. 

The former species has an irregular hyaline ring at or 

near the center of the valve. In C. cirrus the ring is 

much more excentric and composed of large areolae with 

no hyaline space.

This species is one of the most distinctive found in 

the Kettleman Hills. It occurred commonly in both 

samples (1051 and 1052) from the Neverita zone of the 

San Joaquin formation and frequently in one sample 

(1056) from the overlying tuffaceous sandstone. Its 

known geologic range is confined to the Pliocene.

Genus XANTHIOPYXIS Ehrenberg 

Xanthiopyxis ovalis Lohman, n. sp.

Plate 20, figure 6; plate 22, figure 12

Valve oval in valve view and convex in zone view, the 

center 0.003 to 0.004 mm higher than the margin. Surface of valve irregularly covered with short heavy 

spines 0.0015 to 0.003 mm apart. Short striae, averaging 0.001 mm long and spaced 11 in 0.01 mm, project 

inward from the margin, giving a crenulate appearance. 

No spines project outward beyond the margin. Length 

0.020 to 0.030 mm, width 0.014 to 0.019 mm, lengthwidth ratio 1.4 to 1.6.

Measurements of figured specimens: Holotype, no. 

1517-1, length 0.021 mm, width 0.015 mm; paratype, 

no. 1515-2, length 0.027 mm, width 0.018 mm.

Holotype: No. 1517-1, U. S. G. S. diatom collection. 

Collected by W. P. Woodring, May 30, 1932, from 

rodent debris at locality corresponding to a stratigraphic position about 25 feet above the base of the 

Neverita zone, San Joaquin formation, 1,650 feet south 

and 2,100 feet west from northeast corner of sec. 33, 

T. 23 S., R. 19 E., Mount Diablo base and meridian. 

East side of Middle Dome, Kettleman Hills, Kings 

County, Calif., U. S. G. S. diatom locality 1051, Neverita 

zone, San Joaquin formation, Pliocene.

Paratype: No. 1515-2, U. S. G. S. diatom collection, 

collected by W. P. Woodring, December 17, 1931, from 

locality estimated to be 1,500 feet stratigraphically

below the top of the Etchegoin formation, 1,700 feet 

north of southeast corner of sec. 34, T. 24 S., R. 19 E., 

Mount Diablo base and meridian. East flank of South 

Dome, Kettleman Hills, Kings County, Calif., U. S. 

G. S. diatom locality no. 1060, Etchegoin formation, 

Pliocene.

This species is always distinctly oval in outline, and 

the spines never project beyond the margin in th^ plane 

of the valve. Xanthiopyxis oblonga Ehrenberg32 r much 

more elongated, with approximately parallel sides and 

spines projecting beyond the margin. Xanthiopyxis 

hirsuta Hanna and Grant 33 has nearly the same 

shape but much more numerous and much finer spines, 

many of which extend beyond the margin. This diatom 

should receive a new name, as the name hirsvta was 

used by Ehrenberg 34 for a Pyxidicula which Ralfs 3S 

later changed to Xanthiopyxis hirsuta, a form quite distinct from Hanna's species.

It is possible that the genus Xanthiopyxis may represent resting spores of Chaetoceros, but it would iH difficult, if not impossible, to assign the different species of 

Xanthiopyxis to any particular species of Chaetoceros 

until much more is known of both groups. Various 

species of Xanthiopyxis are frequently found in beds 

that never yield even fragments of Chaetocerc?, and 

while this lack might be explained on the grourd that 

species of Chaetoceros are less completely silicifi?-d and 

hence less likely to be preserved, the fact remains that 

many beds which yield Chaetoceros in fairly largo numbers contain few if any Xanthiopyxis. Certain species 

of Xanthiopyxis, furthermore, have been found to have 

short geologic ranges and hence are particularly promising for stratigraphic correlation. It seems best, therefore, to retain the genus Xanthiopyxis.

This species occurs abundantly in the lower part of 

the Etchegoin formation (locality 1060), is distributed 

fairly well through the San Joaquin formation (localities 

1051,1052, 1054, 1056), and occurs rarely in one sample 

(locality 1053) from the Tulare formation. Its known 

geologic range is confined to the Pliocene.

Family EUODIACEAE

Genus HEMIDISCUS Wallich

Hemidiscus ovalis Lohman, n. sp.

Plate 22, figure 9

Valve oval, nearly symmetrical, with the length about 

1% times the width. Cuneate in zone view. Markings round, Iltol2in0.01 mm, arranged in radial rows 

with secondary curved oblique decussating rows evident. Central space large, containing an irregular 

ring of larger, conical granules with one, still larger, 

near the center. Margin narrow, bearing short radial 

striae, 17 to 18 in 0.01 mm. Marginal apiculi absent,

33 Ehrenberg, C. G., Mikrogeologie, pi. 33, group 17, fig. 17,1854. 

33 Hanna, G. D., and Grant, W. M., Miocene marine diatoms from Maria Madre 

Island, Mexico: California Acad. Sci. Proc., 4th ser., vol. 15, p. 170, pi. 21, fig-. 10,1926. 

3* Ehrenberg, C. G., K. preuss. Akad. Wiss. Berlin Ber. Verb., p. 86,1841. 

35 Ralfs, John, in Pritchard, Andrew, A history of Infusoria, 4th ed., p. 827,1861.
92 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1937

but spaces suggesting apiculi occur near the margin 

at intervals of 0.002 to 0.004 mm. A narrow, irregular 

hyaline space occurs along the margin of least curvature, 

causing a break in the otherwise fairly regular markings. 

Length 0.020 to 0.030 mm, width 0.016 to 0.023 mm.

Dimensions of figured specimen, length 0.028 mm, 

width 0.022 mm.

Holotype: No. 1508-1, U. S. G. S. diatom collection. 

Collected by W. P. Woodring, September 30, 1931, 

from tuffaceous sandstone about 105 feet stratigraphically above the base of the Neverita zone, San Joaquin 

formation, 1,430 feet south and 80 feet east from the 

northwest corner of sec. 6, T. 23 S., R. 19 E., Mount 

Diablo base and meridian, cut on south side of Cottonwood Pass road, east flank of North Dome, Kettleman 

Hills, Kings County, Calif., U. S. G. S. diatom locality 

1057. San Joaquin formation, Pliocene.

This species somewhat resembles Hemidiscus margaritaceus (Brun), 36 from the Pliocene of Yedo, Japan, but 

is much smaller, has fewer granules in the central 

space, and is more symmetrical. Bran's species has a 

pseudonodule near the ventral margin. Many species 

of Hemidiscus h.ave a pseudonodule on one valve only, 

and it is entirely possible that the mate to the specimen 

figured may have one. As a large number of individuals 

were examined, and all of them lacked a pseudonodule, 

however, it appears probable that it is normally absent 

on this species. The irregular though definite loop 

formed by the large granules with the single larger 

granule near the center of the central area is a consistent 

feature and clearly distinguishes H. ovalis from H. margaritaceus. In the latter species the granules are much 

more numerous and arranged without order. The 

nearly perfect symmetry of H, ovalis is another consistent feature which distinguishes it. That the two species 

are closely related seems certain, and it is significant 

that both were found in Pliocene rocks, although the 

vague stratigraphic data given by Bran make the 

assignment of his material to the Pliocene uncertain.

This species was found at localities 1056 and 1057 

in the North Dome and at locality 1052 in the Middle 

Dome. Locality 1052 is in the Neverita zone, and the 

other two are in the tuffaceous sandstone overlying the 

Neverita zone. The range of the species is apparently 

restricted to the San Joaquin formation in the Kettleman Hills.

Order PENNALES

Suborder ARAPHIDINEAE

Family FKAGIIARIACEAE

Subfamily FRAGILAKIOIDEAE

Genus RHAPHONEIS Ehrenberg

Rhaphoneis angularis Lohman, n. sp.

Plate 22, figures 6, 7, 8

Valve broadly lanceolate, with tapering, produced 

apices, 0.003 to 0.004 mm wide, near the ends. Central

36 Brun, J., and Tempers, J., Diatomfies fossiles du Japon: Soc. phys. et hist. nat. 

Geneve Mem., tome 30, no. 9, p. 37, pi. 4, fig. 6a, 1889.

portion inflated, with margins forming a distinct angle 

of 135° to 160°. Puncta large, round, arranged in 

parallel to slightly curved, radiating transverse rows, 

5 to 6 in 0.01 mm, and in nearly paralle1 to slightly 

curved longitudinal rows, 7 to 8 in 0.01 ir.m. Transverse rows distinctly radiating in some forms and perpendicular to longitudinal axis in others. Pseudoraphe 

narrow but very distinct, 0.0011 to 0.0013 mm wide. 

Small semicircular areas at apices frequently contain 

2 to 8 very small granules arranged in radial rows or 

without regular arrangement. Length variable, from 

0.050 to 0.150 mm, owing almost entirely to variation 

in the length of the apices. Width much more nearly 

constant, 0.017 to 0.021 mm.

Measurements of figured specimens

U. S. G. S. diatom collection

Holotype no. 1524-1____ 

Paratype no. 1524-2__._ 

Paratype no. 1 524-3 ____

Length 

(mm)

0. 142 

0. 119 

0.066

Width 

(mm)

0. 0195 

0.020 

0.020

Angle

158° 

142° 

137°

Transverse 

rows in 

0.01 mm

5.4 

5.9 

5.9

Longitudinal 

rows in 

0.01 mm

7. 1 

7. 1

All from U. S. G. S. diatom locality 1051. Collected 

by W. P. Woodring, May 30, 1932, from ndent debris 

at locality corresponding to a stratigraphic position 

about 25 feet above the base of the Neverita zone, San 

Joaquin formation, 1,650 feet south and 2,100 feet west 

from northeast corner of sec. 33, T. 23 £., R. 19 E., 

Mount Diablo base and meridian, east side of Middle 

Dome, Kettleman Hills, Kings County, Cal:f. Neverita 

zone, San Joaquin formation, Pliocene.

This species is rather variable in length but remarkably uniform in width, measurements on many individuals deviating not more than 10 percent from the 

mean and only rarely more than 5 percent. The principal distinguishing feature is the definite angle made 

by the margins opposite the center of the valve. The 

most variable feature is the length of the apices. If 

only a form with short apices and one with long apices 

were encountered, they might be considered to be 

separate species. In the large number of individuals 

available from the Kettleman Hills material, however, 

all gradations between the shortest and longest forms 

were found associated in the same sample, r,nd no doubt 

is felt in assigning them all to the same species. In 

some forms the transverse rows of puncta are practically 

straight and parallel to the minor axis, as in plate 22, 

figure 6. Others have somewhat curved, radial transverse rows of puncta, as in plate 22, figures 7 and 8. 

With the exception of these two variable features— 

length of apices and direction of transverse rows—the 

different individuals in a large group are remarkably 

uniform, and the measurements given for the figured 

specimens are typical.

Some of the shorter forms with only slightly rostrate 

apices approach R. rhombus Ehrenberg,37 to which R,

« Ehrenberg, O. G., Mikrogeologie, pi. 33, group 13, fig. 19,185*.
PLIOCENE DIATOMS FROM THE KETTLEMAN HILLS, CALIFORNIA 93

angularis is probably related. It differs from Ehrenberg's species, however, in its distinctly produced rostrate apices, larger and more widely spaced puncta, and 

greater length. According to Ehrenberg's original conception of R. rhombus, it varied from a short rhomboid 

form 38 to a rounded form with stubby rostrate apices.39 

These two forms are probably different species, and 

Hanna 40 has recently selected the first figure cited 

above as the type figure of R. rhombus. This appears 

to be the wisest choice, as it fits the name better than 

the rounded form. Although the shortest forms of 

R. angularis approach R. rhombus and are probably 

related to it, the longer forms with greatly produced 

apices are increasingly different. It seems best, therefore, in view of the confusion which already exists in 

the case of 7? rhombus, to consider the Kettleman 

Hills form a separate species with the relationship 

indicated.

As only the short form (pi. 22, fig. 8) was found hi 

the upper part of the Etchegoin formation, the lowest 

stratigraphic horizon known for the species, it is possible 

that the short form is the parent form of this variable 

species. The long forms differ from the short ones 

only in the greatly produced apices, and it is possible 

that the long forms found in the San Joaquin formation are aberrant developments of the earlier symmetrical form with short apices. This idea is strengthened somewhat by the fact that in the long forms the 

two apices are usually of different lengths. The fact 

that the short form is apparently more closely related 

to R. rhombus, first found in Miocene rocks, than the 

longer forms is further evidence along the same line. 

When these forms were first studied, it was decided to 

make the short form the type of the species and the 

long forms varieties, but as all variations between the 

long and short forms exist, it was impossible to draw 

a sharp boundary between species and variety, and it 

seemed more satisfactory to consider them all as belonging to one species with the variations indicated. 

The possibility that the long forms should be considered varieties of the short form still exists, however, 

and can be settled only by the examination of additional material from the Etchegoin sandstone. In 

making this decision material from the same horizon 

at widely separated geographic localities will be necessary.

This species was found in the Kettleman Hills at 

U. S. G. S. diatom localities 1051, 1052, 1054, and 1058. 

The elongated forms were found only in the Sr,n Joaquin formation at localities 1051, 1052, and 1054. 

Only the short form was found in the upper part of 

the Etchegoin formation, at locality 1058. AH these 

localities are in rocks of Pliocene age.

Rhaphoneis fatula Lohman, n. sp.

Plate 22, figure 5

Valve flat, lanceolate, with gently tapering, produced, 

and slightly expanded apices. Puncta large, round, 

arranged in nearly parallel longitudinal rows, 8 to 10 in 

0.01 mm in central part and 11 to 12 in 0.01 mm near 

apices; and in parallel to slightly radiate transverse 

rows 6 to 7 in 0.01 mm. Pseudoraphe evident bnt not 

pronounced; average distance between longitudinal 

rows of puncta in central part of valve 0.0012 mm, 

width of pseudoraphe in central portion 0.0017 mm. 

Length 0.033 to 0.046 mm, width 0.007 to 0.009 mm.

Measurements of figured specimen, length 0.046 

mm, width 0.009 mm, longitudinal rows of puncta, 

center, 8 in 0.01 mm, apices, 11 in 0.01 mm; transverse 

rows (average) 6 in 0.01 mm.

Holotype: No. 1508-3, U. S. G. S. diatom collection. 

Collected by W. P. Woodring from tuffaceous sac dstone 

in cut on south side of Cottonwood Pass road, 1,430 

feet south and 80 feet east from northwest corner of 

sec. 6, T. 23 S., R. 19 E., Mount Diablo base and 

meridian, about 125 feet stratigraphically above the 

base of the Neverita zone, San Joaquin formation. 

East flank of North Dome, Kettleman Hills, Kings 

County, Calif., U. S. G. S. diatom locality 1056. 

Pliocene.

This species is somewhat similar to R. parilis Hanna 41 

and to R. lancettula Grunow.42 The differences are 

best shown in the following table:

Comparison of species of Rhaphoneis

Pseudoraphe_____ _______ __ _ _

Apices ________ __ ________ ___ ___

Puncta_ ______________ ___ __ ___

R. fatula.

0. 033 to 0. 046_---__-_

0. 007 to 0. 009.. __--.-

4. 7 to 5. !____. -____--

6-7 in 0. 01 mm.

8-12 in 0. 01 mm_-__ -

Round. ___ _ _. _ __

R. parilis

0. 034 to 0. 060__ — — __

0.010.. _._„____.--__

3. 4 to 6. 0.____ — --___

Absent. _______ ___ _

7 in 0.01 mm_____ _

7 in 0. 01 mm___

Not expanded _

Round. ____ ___ ___

R. lancettula

0. 053 to 0. 083.

0. 007 to 0. 010.

7. 6 to 8. 3.

Faint.

5-5J/2 in 0. 01 mm.

No data.

Not expanded.

Quadrilateral.

s 8 Ehrenberg, C. G., op. cit., pi. 33, group 13, fig. 10. 

38 Idem, pi. 18, figs. 81 85.

*» Hanna, G. D., The diatoms of Sharktooth Hill, Kern County, Calif.: California 

Acad. Sci. Proc., 4th ser., vol. 20, no. 6, p. 212, 1932.

« Haana, G. D., The diatoms of Sharktooth Hill, Kern County, Calif.: California 

Acad. Sci. Proc., 4th ser., vol. 20, no. 6, p. 214, pi. 16, figs. 2, 3, 4, 1932.

« Grunow, Albert, in Pantocsek, Josef, Beitrage zur Kenntniss der fossvlen Bacillarien Ungarns, I, p. 35, pi. 27, fig. 271, 1886.
94 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1937

In R. parilis the puncta are "separated uniformly 

from each other",43 from which it may be assumed that 

the spacing of the longitudinal rows of puncta is 7 in 

0.01 mm, the same as is given for the transverse rows. 

The figures do not bear out this statement except for 

the two rows of puncta on each side of the longitudinal 

axis. In general external shape R. fatula is broader 

than R. lancettula and narrower than R. parilis. 

Although the spacing of the transverse rows of puncta

« Hanna, O. D., op. cit., p. 214.

is the same as in R. belgica Grunow,44 the Kettleman 

Hills species is only about half as long, the p^eudoraphe 

is less evident, and the apices are much narrower, with 

enlarged ends.

This species was found in the Kettleman Hills only 

at U. S. G. S. diatom localities 1056 and 1057, where it 

occurred commonly. Both localities are in the tuffaceous sandstone overlying the Neverita zone of the San 

Joaquin formation.

M Grunow, Albert, in Van Heurck, H., Synopsis des diatomees de Belgique, pi. 36, 

figs. 25, 29, 1881.
PLATES 20-23

95
PLATE 20

DIATOMS FROM THE ETCHEGOIN FORMATION

FIGURE 1. Coscinodicus kurzii Grunow. U. S. G. S. diatom catalog no. 1515-1, locality 1060. Diameter 0.135 mm.

2. Coscinodiscus asteromphalus Ehrenberg var. omphalantha (Ehrenberg) Grunow. U. S. G. S. diatom catalog no. 1523-4, 

locality 1058. Diameter 0.266 mm.

3. Coscinodiscus inclusus Rattray. U. S. G. S. diatom catalog no. 1523-B, locality 1058. Diameter 0.040 mn.

4. Endictya robusta (Greville) Hanna and Grant. U. S. G. S. diatom catalog no. 1523-5, locality 1058. Diamete^ 0.057 mm.

5. Coscinodiscus excentricus Ehrenberg. U. S. G. S. diatom catalog no. 1523-7, locality 1058. Diameter 0.066 mm.

6. Xanthiopyxis ovalis Lohman, n. sp. Paratype: U. S. G. S. diatom catalog no. 1515-2, locality 1060. Length 0.027 

mm, width 0.018 mm.

7. Coscinodiscus vetustissimus Pantocsek. U. S. G. S. diatom catalog no. 1523-6, locality 1058. Diamete" 0.066 mm.

8. Actinoptychus undulatus Ehrenberg. U. S. G. S. diatom catalog no. 1523-5, locality 1058. Diameter 0.041 mm.

9. Navicula clavata Gregory var. elliptica Schmidt. U. S. G. S. diatom catalog no. 1523-9, locality 1058. Length 0.072 mm, 

width 0.038 mm.

10. Stephanodiscus dubius (Fricke) Hustedt. U. S. G. S. diatom catalog no. 1523-3, locality 1058. Diameter 0.023 mm. 

96
GEOLOGICAL SURVEY PROFESSIONAL PAPER 189 PLATE 20

X 1000

X 1000

X710

X630

X500

XI070 ^——' XI02°

8 9 10

DIATOMS FROM THE ETCHEGOIN FORMATION OF SOUTH DOME, KETTLEMAN HILLS.

X1560
GEOLOGICAL SURVEY PROFESSIONAL PAPER 189 PLATE 21

X600

X710

X600

X505

X700

X1000

DIATOMS FROM THE NEVERITA ZONE AND OVERLYING TUFFACEOUS SANDSTONE AND CLAY OF THE SAN JOAQUIN FORMATION,

KETTLEMAN HILLS.
PLATE 21 

DIATOMS FROM THE SAN JOAQUIN FORMATION

FIGURE 1. Coscinodiscus obscurus Schmidt. U. S. G. S. diatom catalog no. 1524-7, locality 1051. Diameter 0.118 mm.

2. Coscinodiscus kurzii Grunow. U. S. G. S. diatom catalog no. 1630-3, locality 1052. Diameter 0.105 mm.

3. Coscinodiscus asteromphalus Ehrenberg. U. S. G. S. diatom catalog no. 1508-4, locality 1057. Diameter 0.170 mm.

4. Coscinodiscus cirrus Lohman, n. sp. Holotype: U. S. G. S. diatom catalog no. 1630-1, locality 1052. Diameter 0 121 mm.

5. Coscinodiscus excentricus Ehrenberg. U. S. G. S. diatom catalog no. 1630-2, locality 1052. Diameter 0.066 mm.

6. Coscinodiscus subtilis Ehrenberg. U. S. G. S, diatom catalog no. 1507-1, locality 1054. Diameter 0.071 mm.

	97
PLATE 22 

DIATOMS FROM THE SAN JOAQUIN FORMATION

FIGURE 1. Actinocyclus ehreribergii Ralfs. U. S. G. S. diatom catalog no. 1630-4, locality 1052. Diameter 0.063 mm.

2. Stephanopyxis corona (Ehrenberg) Grunow. U. S. G. S. diatom catalog no. 1524-6, locality 1051. Diameter 0.037 mm.

3. Actinoptychus undulatus Ehrenberg. U. S. G. S. diatom catalog no. 1524-4, locality 1051. Diameter 0.065 mm.

4. Epithemia turgida (Ehrenberg) Kiitzing. U. S. G. S. diatom catalog no. 1524-8, locality 1051. Length, 0.0£ 1 mm, width 

0.019 mm.

5. Rhaphoneis fatula Lohman, n. sp. Holotype: U. S. G. S. diatom catalog no. 1508-3, locality 1057. Length 0.046 mm, 

width 0.008 mm.

6. Rhaphoneis angularis Lohman, n. sp. Holotype: U. S. G. S. diatom catalog no. 1524-1, locality 1051. Length 0.142 mm, 

width 0.020 mm.

7. Rhaphoneis angularis Lohman, n. sp. Paratype: U. S. G. S. diatom catalog no. 1524-2, locality 1051. Length 0.119 mm, 

width 0.020 mm.

8. Rhaphoneis angularis Lohman, n. sp. Paratype: U. S. G. S. diatom catalog no. 1524-3, locality 1051. Length 0.066 mm, 

width 0.020 mm.

9. Hemidiscus ovalis Lohman, n. sp. Holotype: U. S. G. S. diatom catalog no. 1508-1, locality 1057. Length 0.028 mm, 

width 0.021 mm.

10. Nitzschia granulata Grunow. U. S. G. S. diatom catalog no. 1522-1, locality 1056. Length 0.038mm, width 0.016 mm.

11. Nitzschia navicularis Grunow. U. S. G. S. diatom catalog no. 1524-9, locality 1051. Length 0.033 mm, wid*h 0.012 mm.

12. Xanthiopyyis ovalis Lohman, n. sp. Holotype: U. S. G. S. diatom catalog no. 1517-1, locality 1051. Length 0.021 mm,

width 0.015 mm. 

' 13. Melosira recedens Schmidt. Valve view. U. S. G. S. diatom catalog no. 1522-3, locality 1056. Diameter 0.017 mm.

14. Melosira recedens Schmidt. Zone view, five frustules. U. S. G. S. diatom catalog no. 1522-2, locality 105P Diameter 

0.011 mm, length, over all, 0.032 mm.

15. Melosira sulcata (Ehrenberg) Kiitzing. U. S. G' S. diatom catalog no. 1524-5, locality 1051. Diamete^ 0.023 mm.

16. Navicula pennata Schmidt. U. S. G. S. diatom catalog no. 1507-2, locality 1054. Length 0.090 mm, width 0.017 mm.

98
GEOLOGICAL SURVEY PROFESSIONAL BAPER 189 PLATE 22

X 1050

DIATOMS FROM THE NEVERITA ZONE AND OVERLYING TUFFACEOUS SANDSTONE AND CLAY OF THE SAN JOAQUIN FORMATION.

KETTLEMAN HILLS.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 189 PLATE 23

X 1220 X700 X 1000 X700

X900

X 1430

11 12 13 14 15

DIATOMS FROM THE TULARE FORMATION,* KETTLE MAN HILLS.
PLATE 23

DIATOMS FROM THE TULARE FORMATION

FIGURE 1. Surirella utahensis Grunow. U. S. G. S. diatom catalog no. 1520-4, locality 1053. Length 0.030 mm, width 0.024 mm.

2. Stephanodiscus carconensis Grunow. U. S. G. S. diatom catalog no. 1602-5, locality 838. Diameter 0.040 mm.

3. Epithemia zebra (Ehrenberg) Kutzing var. saxonica (Kutzing) Grunow. U. S. G. S. diatom catalog no. 1520-3, locality 

1053. Length 0.058 mm, width 0.010 mm.

4. Rhopalodia gibba (Ehrenberg) Miiller. U. S. G. S. diatom catalog no. 1512-1, locality 1061. Length 0.083 mm, width 

0.022 mm.

5. Hyalodiscus schmidtii Frenguelli. U. S. G. S. diatom catalog no. 1518-1, locality 1053. Diameter 0.039 mm.

6. Eunotia robusta Ralfs var. tetraodon (Ehrenberg) Ralfs. U. S. G. S. diatom catalog no. 1602-7, locality 838. Length 

0.034 mm, width 0.011 mm.

7. Melosira granulata var. curvata Grunow. U. S. G. S. diatom catalog no. 1602-3, locality 838. Diameter O.OC9 mm.

8. Melosira granulata (Ehrenberg) Ralfs. U. S. G. S. diatom catalog no. 1602-2, locality 838. Length (two frustules) 

0.047 mm, diameter 0.013 mm.

9. Melosira ambigua (Grunow) Muller. U. S. G. S. diatom catalog no. 1602-4, locality 838. Length (two frustules and 

two valves) 0.069 mm; diameter 0.016 mm.

10. Diploneis smithii (Brebisson) Cleve. U. S. G. S. diatom catalog no. 1518-2, locality 1053. Length 0.060 mm, width 

0.033mm.

11. Nitzschia punctata (W. Smith) Grunow. U. S. G. S. diatom catalog no. 1602-11, locality 838. Length 0.045 mm, 

width 0.017 mm.

12. Nitzschia etchegoinia Hanna and Grant. U. S. G. S. diatom catalog no. 1520-5, locality 1053. Length 0.096 mm, width 

0.034 mm.

13. Navicula marina Ralfs. U. S. G. S. diatom catalog no. 1519-1, locality 1053. Length 0.066 mm, width 0.035 mm.

14. Cymbella mexicana (Ehrenberg) Cleve. U. S. G. S. diatom catalog no. 1520-2, locality 1053. Length 0.095 mm. width 

0.023 mm.

15. Cymbella prostrata (Berkeley) Cleve. U. S. G. S. diatom catalog no. 1602-9, locality 838. Length 0.048 mm, width 

0.017 mm.

99

INDEX

A Page 

Abstract—_.....__..—_________________________ 81

Acknowledgments for aid_____-—---_ — _-._-___--_--_—-__---_...... 81

Actinocydus ehrenbergii Ralfs___________...______ 83,86,87,88, pi.22 

ehrenbergii var. crassa (W. Smith) Hustedt....___.._____.__ 83

var.ralfsii (W. Smith) Hustedt_———— — „—...— ....—..... 83

var. tenella (Brfibisson) Hustedt_____...................._.. 83

subtilis (Gregory) Ralfs..,..—— .———— ——— —— . ——— ———........ 83,87

Actinoptychussplendens (Shadbolt) Ralfs var_......_________.... 82

undulatus Ehrenberg__..._______________.... 82,86,87,88,89,pis.20,22

cf. A. areolatus Ehrenberg.__ ____________________________________ 82

sp......____________--________.__________._______.___ 82

Amnicola zone, diatom flora of....................._---------_......... 90

AmphoraalHnis Kiitzing...... .......... .............................._.- 84

ovalis Ktttzing—__—————— — ——— ——— ————————— 84

var. libyca (Ehrenberg) Cleve.-....-....-__......_............. 84

Arachnoidiscus cf. A. ehrenbergii Bailey..-.___________._...__ 82 

Asteromphalus brookei Bailey..... — ..._-.-..._____...__-------- 82

Aulacodiscus brownei Norman......_..___.__..._.____._.. 83,87

cf. A. argus (Ehrenberg) Schmidt-__.._-_...._.-..-....._--------_ 83,87

Auliscus caelatus Bailey____.__..._.______.____....__... 83

B

Bacteriastrum hyalinum Lauder__......__..._......._........... 83

Biddulphia aurita (Lyngbye) Brebisson and Godey_.__________.___ 83,87

peruviana Grunow..-_.____.__.__.___„..____._____ 83

roperiana Greville...—_________.......__..._____..._____ 83

cf. B. granulata Roper.._________________.____________ 83

cf. B. pulchella Gray..-- —--_ — - — — ————.. —— --...———— 83

cf. B. reticulata Roper_.__.___.____.-.._.______.___.... 83

Caloneis formosa var. rostrata Frenguelli...__...____.____.__... 84 

silicula (Ehrenberg) Cleve var. kjellmaniana (Granow) Cleve......._.. 84

trinodis (Lewis) Meister.___....__......._........___...... 84

cf. O. formosa (Gregory) Cleve—„_____...____......____. . 84

Campylodiscus clypeus Ehrenberg...._.__....___..........._______ 85,89

echeneis Ehrenberg-._...___.__...__....____.._____..... 85,89

Chaetoceros incurvum Bailey......____._.._.__............___.. 83

Cocconeis placentula Ehrenberg.._._.___............................ 83

placentula var. lineata (Ehrenberg) Cleve-.._______......_........ 83

scutellum Ehrenberg....________________________ .___.... 83

var. baldjikiana Grunow..._____________________________..... 83

var. minutissima Grunow.___________-_-_.____--____-___________ 83,90

sp. undet_-_...__..........._____________________________________ 83

Coscinodiscus anguste-lineatus Schmidt__.____________________________ 82

asteromphalus Ehrenberg,_____________.. __.______ 82,86,88,pi. 21

var. omphalantha (Ehrenberg) Grunow_______-_-.._-____- 82,86,87, pL 20

biangulatusSchmidt.----.______________________________________ 82

bisculptus Rattray...______---_-_____-----______--_.___------____.___. 82

boliviensis Grunow.___._________________________________._-___._._____. 82

cirrus Lohman, n. sp__.______________._________.__._. 82,86,87,88,90-91,pi.21

curvatulus Grunow___ _____________________.___ _________._. 82

denarius Schmidt. ___________________________________.......___ 82

excentricus Ehrenberg..___........._____..____. 82,86,87,89, pis. 20,21

gigas Ehrenberg.._____________________._..._________ 82

inclusus Rattray______________________________________ 82,86, pi. 20

kurzii Grunow..______________________________ 82,86,87,88,pis. 20,21

kiitzingii Schmidt-.—— — -- — — — _- —— ———— — — — — __———_ 82,89

lineatus Ehrenberg..-_..________________________________. 82

obscurus Schmidt.......___........________________________ 82,88,pi. 21

oculus-iridis Ehrenberg..___......._____-.____________________ 82,85,88

paciflcus Grunow—--.________.________.___________. 82

radiatus Ehrenberg-..______.______.______._____. 82,88

rothii (Ehrenberg) Grunow var. normani (Gregory) Van Heurck.________ 82

spinuligerus Rattray...-.__.---..........-.....__.-__-.___________-__ 82

stellaris Roper__________________---__-_---___________-_-__.__________. 82

subtilis Ehrenberg______________._________________________ 82,85,87,88,91, pi. 21

vetustissimus Pantocsek____._____ —— —— ____———_.____. 82,86,91, pi. 20

cf. C. cribrosus Truan and Witt___.__________________________________ 82

cf. C.elegans Greville...-____________________________________________ 82

cf. C. janischii Schmidt_________________________________________________ 82

Page

Cyclotella compta (Ehrenberg) Kutzing var. pliocaenica Krasske____._. 82,89 

irisBrunandHeribaud----—————- — ----------- —--------- 82,89

meneghiniana Ktttzing......—.———.—....——— ——. — .«- 82,89

pygmaea Pantocsek...._____.......———..—————...———— — 82,89

striata (Kutzing) Grunow.— ——————— —————— — —— — —— 82

Cymatopleura sp__...__.--_------- — _. — — -—--------- —. —.. 85

Cymbella cistula (Hemprich) Kirchner.__.__..__ —— ——————— _—— 84 

cuspidata Ktttzing.............. — .-„.-. — .— —— -———..-.-— 84

cymbiformis (Ktttzing) Brebisson.— ..——___ — ————.————.—— 84 

lanceolata (Ehrenberg) Kirchner_........——...———.——————.—— 84

mexicana (Ehrenberg) Cleve—------------------------------------ 84,89,pi. 23

parva (W. Smith) Van Heurck..... — ............-„„- — ..—...-.. 84

prostrata (Berkeley) Cleve—„-.-..„. —— — „---- — —— -— 84.89,pi. 23

ventricosa Ktttzing..._______.___.——. ——— ——— —..„—— 84

D 

Dicladia capreolus Ehrenberg----.-------------------------------------- —— — 83

Diploneis advena (Schmidt) Cleve...--___.______.____ — ___ 84,90 

elliptica (Ktttzing) Gleve.........—..————.—. — .——.. — ——„ 84

smithi (Brebisson) Cleve.——————— ———— ———————— &' 89,pi. 23

Dossettiasp..—— — — — ————————--————.———— —— — 83

E 

Endictya oceanica Ehrenberg—...._-------- — -_-._. —.... — _ ——..—— 82

robusta (Greville) Hanna and Grant- — —. ———————„.— 82,86,pi. 20 

Epithemia argus (Ehrenberg) Katzing--.— -———— — —— — ——— ——— 84

sorex Ktttzing....-------—.—------------------------------------------ 84

turgida (Ehrenberg) Kutzing——...... — . — — ——.— .. 84,85,pi. 22

var. granulata (Ehrenberg) Grunow.--_ — _-__ _________-_--_..— 84

var. westermanni (Ehrenberg) Grunow.-..---._______...__. 84 

zebra (Ehrenberg) Ktttzing.-..—....„_...- —— „- — „..-. —— ....-„ 84,90

var. porcellus (Ktttzing) Grunow..... __.-._._..._ — __ ———...—— 84

var. saxonica (Kutzing) Grunow...-- — ——--- —— „- — — &',90,pl. 23 

Etchegoin formation, age of—__-..-___-..-._---_-_-----------.-_____------- 81

definition, thickness, and occurrence of-__-__-----__ — --—____--_____-_— 85

diatom flora of-...._—— ———— ——— „ — —— ———— ———— -. £2-85,87-88

lower part of, diatom flora of....--.____.-_--_.____-_-.___----___-_-_--. 85-86

upper part of, diatom flora of___--_—- —— _—------- —— _ — _ — ——. 86-87

Eunotia formica Ehrenberg—___._-..-_-_..--_____ ———... —. — _—— 83

lunaris (Ehrenberg) Grunow....___ — .—...---.- — _______ —...— 83

pectinalis (Kutzing) Rabenhorst__...„„-.._____-_--..-___--____.__ 83

var. minor (Ktttzing) Grunow.._____--._---_____-___-__.... — . 83

var. undulata (Ralfs) Rabenhorst._...............-._ — ...----_.„.. 83

var. ventralis (Ehrenberg) Hustedt—-.—--.. — ..---.- — —...... —. 83

praerupta Ehrenberg.-_...——.———__---.____.-_. ——.. —— _———. 83

robusta Ralfs var. tetraodon (Ehrenberg) Ralfs. _---_-___._...-._-_- 83,89, pi. 23 

serpentina Ehrenberg_„__„. —.__..„ — — — -- — -.- — . — .-- — -.— 83,89 

tenella Grunow (Hustedt)----- — -- — - — - — ------------- ——— 83

trigibba Hustedt--— — ——— — ——— -_„ — — — - — ——— — — 83

cf. E. didyma Grunow var. curta Hustedt—.__.____.__.___-. — ..„.. 83

cf. E. gracilis (Ehrenberg) Rabenhorst._...______-_-_._._-___-_-_-._ 83

Fragilaria construens (Ehrenberg) Grunow__.___._...____. — „_. 83

construens var. subsalina Hustedt...___.--_______-_...-.-.-.-.____-- 83

var. venter (Ehrenberg) Grunow....___........--._........-..__. 83

harrissonii W. Smith..—--.-------------.-------------------------------- 83

W. Smith var. dubia Grunow..______.._____.....____... 83

G

Gomphoneiselegans (Grunow) Cleve—___----_.-__--_____-___----__--__-__ 84

herculeana (Ehrenberg) Cleve_-__-_____.___...__-________.-. 84

mamilla (Ehrenberg) Cleve__ —...„.__..._.-_._-.___---------- 84

cf. G. herculeana var. robusta Grunow __.__---..__-_---_-_____-__--_-_.- 84

Gomphonema acuminatum Ehrenberg var. turris Ehrenberg- _______...... 84

augur Ehrenberg var. gauteri Van Heurck—_....___-_._-_-_-_-_.___--- 84

constrictum Ehrenberg.______......._--_._---___-_-_.___- 84

intricatum Ktttzing—- -- - - - ---- - ----------------- 84

scapha M. Schmidt___.-..--- — -.-..-_-_-_.--_____-__--_-_-_-___-_-___- 84

Goniothecium rogersii Ehrenberg,--.---_.___-_-_--___..___-_-_-__-__-______ 83

Grammatophora cf. G. maxima Grunow_.........-.-....._. —........... — . 83

Grunoviellagemmata (Grunow) Van Heurck-—_____-—._ ——— ——— — 83

Gyrosigmaattenuatum (Kutzing) Rabenhorst—-______ ____-_.___-___.-____- 84

kutzingii (Grunow) Cleve-.-.-- ———— — -------- — — ——— -- 84

101
102 INDEX

H Page

Hanna, Q. D., quoted_________________.______..____ 86-86 

Hantzschia amphioxys (Ehrenberg) Grunow.____.__..____._.. 85 

Hemidiscus margaritaceus (Brun).___________________ 87,92 

ovalis Lohman, n. sp.—___...______________ 83,87,88,91-92, pi. 22 

Hercotheca cf. H. mammillaris Ehrenberg____....____________ 83 

Hyalodiscus schmidtii Frenguelli__._____________.___ 82,89, pi. 23

Kettleman Hills, Calif., check list of Pliocene diatoms from__________ 82-85 

stratigraphic features of.___________________._______ 85-89 

structural and topographic units of..___________________. 81

Kreyenhagen shale, impressions of diatoms in..________ ______.. 90

Liradiscusoblongus Grunow._________._...._____.__..._ 83 

Lithodesmium cf. L. cornigerum Brun.-__.__..._.__.__. ..._. 83,85 

Lithodesmium sp..._,-...._________.______....___.... 83,87

M

McLure shale, impressions of diatoms in...__._...__..._........._ 90

Mastogloia elliptica Agardh___________.—....____.-._-._.____ 84

Melosira ambigua (Grunow) Miiller.....-——.-__.__.-..__..-___-__. 82,89, pi. 23

crenulata Kiltzing var. semilaevis Grunow__._..................._ 82

distans Kiitzing var. lirata (Ehrenberg) Bethge.._.._...._______ 82

granulata (Ehrenberg) Ralfs._—__..______..._..._ 82,85,89,pi. 23 

var. australiensis Grunow...______.__....._...____..... 82

var. curvata Grunow_____________....._.___.. 82,85, pi. 23

var. muzzanensis (Meister) Bethge...-..-..-----_-----.-----.....__ 82

italica (Ehrenberg) Kiitzing.______.__.___..__._______ 82 

polaris Grunow...———....-..--_........__._............____ 82

recedens Schmidt-——.__.___.__..__._...___ 82,87,88,pi. 22 

sol (Ehrenberg) Kutzing—.............................................. 82,89

solida Eulenstein_____.___. ___.__. __.. _. ___._ 82 

var. haitiensis Grunow______....__..___._________ 82,85

var. multiformis Frenguelli—--.-.______---------_______ 82,86

sulcata (Ehrenberg) Kiitzing................................. 82,87,88,89,pi. 22

undulata (Ehrenberg) Kiitzing var. normanii Arnott.__________ 82 

cf. M. clavigera Grunow_...____...______.__........___ 82

cf. M. islandica Miiller...................__............................ 82

Meridion circulare Agardh__.______._________________ 83

N 

Navicula amphibola Cleve.___....._-..._..........._._.___... 84

clavata Gregory var. elliptica Schmidt-...__.__.____..._ 84,87, pi. 20 

cuspidata var. heribaudi M. Peragallo. ....._....__..____....... 84

exigua (Gregory) O. Miiller—_.__....___........_____...._ 84

gastram Ehrenberg-——_______..____.__....____..__ 84

hennedyi W. Smith.—.-——__. —.—.-___.._...-_._._——...______ 84

lyra Ehrenberg__------___.__....______.______.___ 84

marina Ralfs.__....___...___.__.______.____.. 84,89,pi. 23

pennata Schmidt______._______...___________._ 84,88.pi. 22

var. kinkeri Pantocsek—__—_____..._... ___...._____ 84,90 

peregrina (Ehrenberg) Kiitzing var_....____...____...___ 84,89 

pupula Kiitzing var. capitata Hustedt...___.._____...___ 84

var. rostrata Hustedt....______..._......_____.__ 84

radiosa Kutzing-.——.._..._----------____..____...____ 84

var. tenellaBrebisson__--------_-.__...___.______ 84

tuscula Ehrenberg-.—__......__--.._.- — __ — .__--____.__.. 84

cf. N. cuspidata Kiitzing_....___.___.........._.___.___ 84

cf. N. subtilissima Cleve_______.___.__.__.....__.___ 84

Neverita zone, diatom flora of.___.__.___..._...-_-_.--__-. 82-85,87-88 

tuffaceous sandstone overlying, diatom flora of._._.._...._.___ 88

Nitzschia etchegoinia Hanna and Grant__....____..____... 85,86,89,pi. 23

granulata Grunow__._.______.______________ 85,88,89, pi. 22 

navicularis Grunow__......_______________....______ 85,pi. 22

punctata (W. Smith) Grunow..._———..———————_.——— 85,89, pi. 23 

scalaris (Ehrenberg) W. Smith.______.....____.______._ 85

tryblionella Hantsch var. maxima Grunow..__..____._........... 85

var. victoriae Grunow__________.____.______._ 85 

cf. N. denticula Grunow_______________....._.___..._ 85

O Page

Omphalotheca sp_________-___.__..__..._....___._.... 83,88 

Opephora schwartzii (Grunow) Petit.._____._,—..———.-—__.————.. 83

Periptera tetracladia Ehrenberg....._.__.__._.......___._-..---. 83

Pinnularia borealis Ehrenberg___....__...-———— —..——-_.--..—— 84

dactylus Ehrenberg______-....____—...——.-.---..-..---.— 84

fasciata (Lagerstedt) Hustedt———.. ————.—————————————— 84

hemiptera Ktttzing.___—————_——... —————————————... 84

major (Kiitzing) Clove.—_......__—.— —————-.—————. 84

nobilis Ehrenberg._______——..—....——.——.——-—...—— 84

cf. P. major var. subacuta (Ehrenberg) Cleve-__-----_.__—..—— 84

cf. P. subcapitata Gregory—..—______-__——____-.....---- 84

cf. P. viridis (Nitzsch) Ehrenberg-___.____._.______..---. 84

Pleurosigma strigosum W. Smith_.______—_—-------_---------- 84

cf. P. afflne Grunow____..„——____—————..—--------——— 84

Podosira febigeri Grunow--..---._.____.__— — —...__...- — .---— 82

hormoides (Montague) Kiitzing var. adriatica Grunow.____."-........ 82

stelliger (Bailey) Mann.----.—----—..--.-.------------------.--------- 82,89

B 

Rhaphoneis aflmis Grunow_-__.-.-_........ — .„.„....__————— 83

amphiceros Ehrenberg_...__ —...-—_-.---. —. —-....————— —— 83

angularis Lohman, n. sp..— .—..—......— — ~..~ 83, 86, 87, 88, 92-93, pi. 22

belgica Grunow._____.....——...—... ——... —. ———————.—— 94

fatula Lohman, n. sp.___....______....._-—..-— 83,88,93-94, pi. 22

lancettula Grunow.-------------------------------------——-- 93,94

parilis Hanna-_................-.-.-.-......——---„- — .——.— 88,93,94

rhombus Ehrenberg..___._-__.........——..—.. — — .——„..„ 92-93

cf. R. morsiana Grunow...-..----._.--_-_-_..--.-. —. —__——— — 83

Rhizosolenia sp______...--.- — _..._..- —— -. ——.. —..— —.-.. 83 

Rhoicosphenia curvata (Kutzing) Grunow——..- —————...——.————— 83 

Rhopalodia gibba (Ehrenberg) Miiller_...........................— 84,90,pi. 23

gibba var. ventricosa (Ehrenberg) Miiller--——-———...._————— 84,90

gibberula (Ehrenberg) Miiller...._____......——..._....__... 84

S

San Joaquin formation, age of.—————..-. ——— —— ----- —— ---.-...—— 81 

definition and divisions of...__..._ —. —.—.——...—..- — -—— 87 

diatoms from.-------_...--..-.--._...-.. — --.-.---..--......—-—— 82-85

Stauroneis parvula Grunow.. — ————.— ——————.. ————— -—— 84 

phoenicenteron Ehrenberg—————_.... ——————. ——————.—— 84 

cf. S. anceps Ehrenberg var. gracilis Ehrenberg———————————_—— 84

Stephanodiscus astraea (Ehrenberg) Grunow.--—————...———————— 82

carconensis Grunow.__. —.———..— —... — -- — — — -— 82,89,pi. 23

var. pusilla Grunow.______.___._-_—.__.„..-—-f~ 82,89

dubius (Fricke) Hustedt------------.-.---...---------------.--- 82,86,pi. 20

Stephanogonia sp......___ ——..-.._ ——.... ———... — ———.——— 83

Stephanopyxis bruni Schmidt var......_... —. — —....._ —. —— ——— 82

corona (Ehrenberg) Grunow.__._.______.——__..-. 82,87,88,pi. 22 

turris (Grevilleand Arnott) Ralfs____.___......____———— 82

var. cylindrus Grunow__.________ ————.__.__—...— 82,90

Surirella striatula Turpin——.—.—.....— — „-. — .—..--.——————— 85,89 

utahensis Grunow..,__....———.-.....—-—.. — --.——-.— 85,89,pi. 23

Syndendrium diadema Ehrenberg-——_—.————....... ————.——— 83

Synedraulna (Nitzsch) Ehrenberg-——_—.———————.—————.—— 83 

ulna var. amphirhynchus (Ehrenberg) Grunow—————.———.——— 83

T 

Terpsinoe americana (Bailey) Ralfs..—__..---.———.......—.-..- — — —— 83,89

Tetracyclus japonicus (Petit) Hustedt——.—....——..—.....—..———— 83

lacustrisRalfs..—..————.—.—— ———.———-——-.- 83

Thalassionema nitzschioides Grunow—__--..-. —— — --.-..-—.—...— 83 

Thalassiosira decipiens (Grunow) Joergensen.......__.....___.....__-. 82,89

Triceratium uncinatum Schmidt.——_.___...._————.—-—„—.... 83,89

Tulare formation, age of.___..._—._„ — ....———... —————— — 81

definition, thickness, and occurrence of.. — ..... ————...——————— 88

diatom flora of..._____—-...--__..........————.——. 82-85,88-90

Xanthiopyxis cingulata Ehrenberg--—.____...-. — .. —...——...——— 83 

hirsutaHannaand Grant__.. — ______—— — ..-..—...—.—— 91

oblonga Ehrenberg.._____.__.___....__—__....—...— 83,91 

ovalis Lohman___————————..._—————. 83,86,87,88,89,91,pis. 20,22

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