THE REEF-CORAL FAUNA OF CARRIZO CREEK, IMPERIAL COUNTY, 

CALIFORNIA, AND ITS SIGNIFICANCE. 

By THoMAS WAYLAND VAUGHAN. 

INTRODUCTION. 

Knowledge of the existence of the unusually 

interesting coral fauna here discussed dates 

from the exploration of Coyote Mountain (also 

known as Carrizo Mountain) by H. W. Fairbanks in the early nineties. 1 Dr. Fairbanks 

sent the specimens of corals he collected to 

Prof. John C. Merriam, at the University of 

California, who in turn sent them to me. 

There were in the collection representatives of 

two species and one variety, which I described 

under the n·ames Favia merriami, 2 Stephanocmnia fairbanksi, 3 and Stephanocmnia fa{rbanksi var. columnaris.4 As the geologic horizon was not even approximately known at that 

time, I gave it as "doubtfully Cretaceous" in 

the paper cited. 

Late in 1903 Dr. Stephen Bowers sent to me 

for examination a small collection of fossils 

obtained by him in the Carrizo Creek area during June and July, 1901.5 This collection contained corals whose affinities are undoubtedly 

with Pliocene, Pleistocene, and Recent species 

of the western Atlantic region, and not with 

any known living Indo-Pacific fauna. The following statement was mad~ in a pa.per based on 

this collection.6 

In the collection that has so far been made from the 

California fossil reef five genera are represented, all of 

which occur in the fossil and recent faunas of the Antilles 

and not one of which is at present known to occur on the 

Pacific coast. The age of the beds in which these fossils 

1 California State Min. Bur. Eleventh A!nn.. Rept., pp. ·83-90, 1893. 

2 Vaughan, T. W ., The Eocene and lower Oligocene coral faunas of the 

United States: U. S. Geol. Survey Mon. 39,p.142,pl.15,figs. 5,5a, 5b, 5c, 

1900. 

a Idem, p . 151, pl. 17, figs. 11, lla. 

• Idem, pp. 151, 152, pl. 17, figs. 10, lOa. 

~ A brief report on his field observatioiJs was made by Dr. Bowers in 

an article entitled "Reconnaissance of the Colorado Desert mining 

district," 19 pp., California State Min. Bur., 1901. 

6 Vaughan, T. W., A Californian Terti3ify coral reef and its bearing on 

American recent coral faunas: Science, new ser., vol. 19, p. 503, Mar. 24, 

1904. 

occur has been determined by Drs. Arnold and Dall to be 

lower :Miocene. The following conclusions seem warranted: 

(1) There was water connection between the Atlantic and 

Pacific across Central America not much previous to the 

upper Oligocene or lower Miocene-that is, during the 

upper Eocene or lower Oligocene. This conclusion is the 

same as that reached by Messrs. Hill and Dall, theirs, however, being based upon a study of the fossil mollusks. (2) 

During lower :Miocene time the West Indian type of coral 

fauna extended westward into the Pacific, and it was subsequent to that time that the Pacific and Atlantic faunas 

have become so markedly differentiated . . 

As it will be made evident on subsequent 

pages that this fauna is much younger than 

lower Miocene, the inference as to the date of 

the interoceanic connection given in the foregoing quotation must be modified. t 

After receiving the specimens from r. Bowers and recognizing the need of mor careful 

geologic studies in the Carrizo Cree · arPa, I 

brought the matter to the attention · f C. W. 

Hayes, then chief geologist of the Su ey, and 

in January, 1904, arrangements were ade for 

an expedition to the region, in charge of W. C. 

Mendenhall, who was accompanied by Dr. 

Bowers. Mr. Mendenhall conducted he physiographic and stratigraphic studies and Dr. 

Bowers made a large colle~tion of fos ils. 

As it was my intention to publish romptly 

an account of the fossil corals, I fur ished to 

Ralph Arnold, for publication in s paper 

entitled ''The Tertiary and Quaterna .,. pectens 

of California," 7 a list which contai ed three 

nomina nuda, but other duties prev nted my 

completing a report until the summe of 1916. 

The list furnished and published was based on 

the collection submitted by Dr. Bow rs before 

he made the expedition with Mr. Me denhall. 

It is given in the first eolumn of t e list on 

page 356. The second column gives t e names 

applied in this paper. 

1 U. S. Geol. Survey Prof. Paper 47, p. 22, 19 

355 
356 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1916. 

Fossil corals from Carrizo Creek, Cal. 

Name in Prof. Paper 47, p. 22. Revised name. 

Diploria bowersi Vaughan Mreandra bowersi Vaughan. 

(MS.). 

Favia merriami Vaughan. 

Plesiastrea c a 1 i f o r n i c a 

Vaughan (MS.). 

Siderastrea c a 1 i f or n i c a 

Vaughan (MS.). 

Stephanocrenia fairbanksi 

Vaughan. 

Stephanocrenia fairbanksi 

var. columnaris Vaughan. 

Dichocrenia merriami 

(Vaughan). 

Solenastrea fa i r b a n k s i 

(Vaughan). 

Siderastrea c a l i f o r n i c a 

Vaughan. 

Solenastrea f a i r b a n k s i 

(Vaughan). 

Solenastrea fairbanksi var. 

columnaris (Vaughan). 

some of the photographs. The illustrations 

showing the geologic conditions under which 

the fossil corals occur are reproductions of 

photographs taken by Mr. Mendenhall, and 

I am making extensive quotations from his 

article entitled "Notes on the geology of 

Carrizo Mountain and vicinity, San Diego 

County, Cal." 1 

GEOGRAPHIC RELATIONS. 

The accompanying sketch map (fig. 43) is 

taken from the article by Mr. Mendenhall, who 

FIGURE 43.-Sketch map of Coyote Mountain, Cal., and vicinity, showing localities in Alverson and Barrett canyons where fossil corals were 

collected. (After Mendenhall.) 

Messrs. Mendenhall and Bowers shipped to 

Washington over 400 specimens of corals, and 

it is on this large collection that the present 

paper is mostly based. All the photographs of 

corals herein illustrated were made by Mr. W. 

0. Hazard, except those for Plate XCIX, which 

were contributed by Dr. Charles Gravier, of 

Paris. Miss Frances Wieser has retouched 

gives the following graphic description of the 

general geographic relations: 

Black and Carrizo mountains, known also as Fish Creek 

and Coyote mountains, are eastern outliers of the Peninsula 

Range that separates the depression occupied in part by 

the Gulf of California from the Pacific Ocean. They are 

in southeastern California near the western edge of the 

t Jour. Geology, vol. 18, pp. 336-355, 1910. 
REEF-CORAL FlAUNA OF CARRIZO CREEK, IMPERIAL COUNTY, CAL. 357 

Colorado Desert and from 15 to 30 miles north of the inter- representatives in this region. Either the Ca 

national boundary. East of them the Colorado Desert, Black Mountain areas were land masses subject t erosion 

much of it below sea level, extends to the Colorado River, during this interval or the evidence of such p riods of 

while to the west low ridges extend to the base of the main deposition as intervened was later removed by · rosional 

Peninsula Range. processes. 

The two masses are separated by the valley of Carrizo The Miocene 3eems to have been inaugurated by valCreek. This stream rises in Mexico, flows north for several canic activity. On the southern slopes of both Ca izo and 

miles, through a high valley in the :Peninsular Mountains, Black Mountains are bedded tuffs, volcanic conglo erates, 

then descends to the desert level through a precipitous and less extensive masses of dark lavas of andesiti aspect. 

canyon. Nearly all of that part of its channel that lies On Black Mountain there are distinct sandston s interwithin the desert is dry except during rare flood periods, bedded with these and directly upon them lie the Miocene 

when its waters join those of San Felipe Creek, north of coral reefs. In Alverson Canyon, which drains so th from 

Black Mountain, and eventually reach the Salton depres- Carrizo Mountain, red vesicular lavas are succe ded by 

sion. At Carrizo Station, one of the relief stations of the green and lavender sandstones and conglomerate , whose 

old Butterfield stage line, a series of iilprings rise, and for 1 constituent materials are volcanic, and these in t rn grade 

to 2 miles below this point flowing water is found in the into conglomerates with a diminishing proportio of valcreek bed except during the hottest period of summer. canic pebbles. Above them are quartz congl merates, 

The desert floor at the eastern ba$e of the peaks is gen- tawny sandstones, and finally soft greenish-yel ow clay 

erally from 100 to 200 feet above sea level, but on the north shales. 

side of Black Mountain the sea-level contour and the old An unconformity which is not especially co picuous 

beach of Lake Cahuilla, 40 feet above sea level, swing exists in the Miocene between the sandy shel -bearing 

in against the mountain base. In the past the region beds, 100 feet or less in thickness, which immedia ly overhas been rather difficult of access 

PLEISTOCENE. MIOCENE PALEOZOIC 

because of its remoteness from 

settlements and its aridity. With 

the colonization of the Imperial 

Valley since 1900 and the building 

of the branch railroad from Qld 

Beach to Calexico, however, this 

condition has been greatly modified. 

Now Carrizo Station or Coyote 

Well may be reached by one day's 

drive from Imperial or El Centro, 

and supplies are readily secured at 

many points in the valley. The 

~-Alluvium Shale Sandstone ~ . ~ Tuff .Lime?tonewith and conglomerate ~ntrustve gramtessb:! . both metamorphol 

FIGURE 44.-Diagrammatic section across Coyote Mountain, Cal., by way of Alverson d Gamet 

canyons. (After Mendenhall.) 

old roads from the desert to San Diego, the one running 

north of Carrizo Mountain by way of Julian and the other 

south of the mountain by way of Jacumba and Campo, 

are still much used for direct communication between 

the Imperial Valley and the coast, although the Campo 

road below Mountain Springs is rough and after storms is 

nearly impassable. 

GEOLOGIC RELATIONS. 

The following is Mendenhi\ll's account of the 

broader geologic relations within the area: 

Carrizo [Coyote] and Black [Fish Creek] mountains are 

islands of granitic and metamorphic rocks which rise 

through encircling terranes of later sediments and volcanics. These later beds are Miocene and younger, and 

the unconformity which exists between them and the older 

rocks upon which they lie is profound. The time interval 

represented by this unconformity is not known, because 

the age of the altered rocks below it is a matter of uncertainty. Fairbanks 1 expresses the opinion that they are 

Carboniferous or older, the opinion being based presumably upon their general resemblance to upper Paleozoic 

socks in other parts of California and upon the aspect of 

rome shells found in a float piece of siliceous limestone. 

Accepting this determination as the best possible in the 

state of our knowledge, we must conclude that the Triassic, 

Jurassic, and Cretaceous systems are without depositional 

1 Fairbanks, H. W ., California State M)ineralogist Eleventh Rept., 

pp. 88-90, 1893. 

lie the volcanics or the metamorphics, and the eat mass 

of shales, greenish or yellowish at base, pink or p le red in 

general color tone toward the top, which form th badland 

area that is especially well developed between lack and 

Carrizo mountains. Finally, across the planed edges of 

these shale beds, a sheet of river cobbles, well rou ' ded, has 

been distributed unconformably throughout th Carrizo 

Valley. They are probably Pleistocene but a e earlier 

than the silts, sands, and gravels, which represe t the offshore and beach deposits of the lake which unti recently 

has occupied the Colorado Desert. The latest e osion has 

left these old stream deposits stranded upon th~emnants 

of the ear.lier valley floor at heights of from 100 t 200 feet 

above the present bed of Carrizo Creek. 

Figures 44 and 45 are copied from endenhall's papP.r, and the accompanying sketch 

geologic n1ap (fig. 46) is taken from a p per by 

K ew. 2 It should be noted that the na e Carrizo sandstone, shown on this map, h s been 

in use since 1889 for a geologic form tion of 

Eocene age exposed along and near he Rio 

Grande in Texas, and since 1891 for a Algonkian(~) formation in western Texas. T e name 

therefore can not be properly applied o these 

California deposits. . 

2 :Kew, W. S. W ., Tertiary echinoids of the Carrizo Creek r gion, in the 

Colorado Desert: California Univ. Dept. Geology Bull., vol. . , p. 41,1915. 
358 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1916. 

GEOLOGIC HISTORY. 

The following outline of the geologic history 

of the area is also . taken from the article by 

Mendenhall: 

The story of the development of this part of the country 

can not be read with any approach to accuracy as yet for 

any period beyond the Miocene. The rocks which represent earlier time are marmarized limestones, schists, 

and gneisses, as to whose age there is much doubt. The 

slight existing evidence points toward the Carboniferous 

as the period during which the limestones were deposited 

here. Whatever their age, their condition now indicates 

that their history previous to the Miocene was one involving deep burial and intense earth strain. They were 

upturned, intruded, and crystallized, uplifted and eroded 

2001 

Fossiliferoua sandstone 

~~:~~~rs1~ fo~~il6 in Garnet canyon 

FIGURE 45.-columnar section of rocks exposed in Garnet Canyon, Cal. 

(After Mendenhall.) 

into a mountainous topography, and at the beginning of 

the late Miocene formed islands in a sea teeming with life. 

Volcanic forces were active at this time, and the flanks of 

the old land mass are partly buried under the effusive 

material which issued then, and the muds and the littoral 

whose fragments were supplied from volcanic sources are 

conspicuous at many points. But as the period advanced 

volcanism ceased, and the present Carrizo and Black 

mountains were surrounded and perhaps for a part of the 

time were submerged beneath a clear sea in which the 

myriad forms of the life of the period swarmed. Still 

later in the Miocene the character of the sea changed. 

Instead of clear, salt water, some realignment of forces 

caused great quantities of muddy, brackish water to spread 

about the old islands. Oysters of many forms, some of 

them of great size, some very tiny indeed, flourished. 

The heavy silts of these · muddy waters accumulated to 

great depths as the land subsided. Finally the waters 

withdrew, presumably because of reelevation, and the 

region was land again as it had been before, and the shells 

of many of the creatures which had lived in the clear and 

then in the muddy waters were preserved in the accumulated sediments. As the sea withdrew the destructive 

forces of weathering and the erosive forces of wind and 

running water became active. The clays which had accu.;. 

mulated were now dry and were cut away again by these 

forces. The process was not long continued and the plain 

was not completed, those clay areas which were capped 

by protecting sandstones remaining as monadnocks above 

the wide valley floor. This valley, occupied by an earlier 

vigorous ancestor of Carrizo Creek, was strewn with 

rounded river cobbles brought from the higher mountains 

to the west. South and east of Carrizo Mountain large 

areas seem to have been reduced at this period well toward 

the condition of a peneplain. This plain lies perhaps 200 

feet above the later Pleistocene lake level, with which it 

seems to have no connection. It is regarded as an earlier 

independent feature, perhaps Pliocene in age. 

After the formation of this partially planed surface over 

the soft rocks of Carrizo Valley some change, either in the 

relations of land and sea or of climatic conditions, enabled 

the streams to dissect it again. The result of this dissection, which may well have been contemporaneous with 

the last occupancy of the Colorado Desert by the Gulf of 

California, is seen in the Carrizo Creek badlands of to-day. 

The last important element in the development of the 

geography of this part of the desert was the formation and 

the disappearance of the desert lake. So late is it that the 

calcium carbonate incrustations which it left on its western shore show but little effect of erosive or solvent action 

since the waters left them, and the sandy beach, molded 

by the waves of the lake upon the alluvial fans which 

formed a large part of its shores, is still well enough preserved to be readily traced. Only the most modern 

gullies have cut it away. At one point a low sea cliff 

notched by the waves in steep alluvial-fan material still 

stands, as perfectly preserved as though the waters had 

just withdrawn. 

THE CORALLIFEROUS BEDS. 

The fossil corals occur in that part of the 

columnar geologic section designated ·' 'Miocene 

conglomerates, " by Mendenhall. The following is his description of these beds: 

In the lower part of Alverson Canyon a heavy conglomerate bed 120 to 130 feet thick overlies a seri s of tuffaceous 

strata. This bed is composed of coarse ·naterial at the 

base but becomes finer at the top. It is only moderately 

hard, and along its upper margin · is an abundantly fossiliferous horizon. Splendid coral heads are embedded in 

these sandstones, and more delicate forms are found at 

the base of the superjacent sandy shaies. These corals 

with the molluscan remains that accompany them, all of 

which await detailed examination and determination, 

prove the age of the inclosing rocks to be upper :Miocene. 

[See Pl. XCII.] 

On the north slope of Carrizo [Coyote] Mountain, about 

the head of the easternmost arroyos which are tributary 

to Garnet Canyon, another series of fragments of a well-
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 98 PLATE XCII 

A. VIEW LOOKING DOWN ALVERSON CANYON FROM A POINT NEAR ITS HEAD. 

Coyote Wells Valley in the middle distance. Fossil corals and mollusks are found all along the canyon in 

sandstones overlying shales. 

B. VIEW LOOKING N. 35° W. ACROSS THE MOUTH OF ALVERSON CANYON, FROM COYOTE 

WELLS VALLEY. 

The fossiliferous Pliocene beds through which the shallow canyon is cut are shown in the middle ground. 

VIEWS OF ALVERSON CANYON, IMPERIAL COUNTY, CAL. 

Photographs and explanations by W. C. Mendenhall. 

REEF-CORAL FAUNA OF CARRIZO CREEK, IMPERIAL COUNTY, CAL. 359 

developed basal conglomerate are encountered. They spread out over the sandstones were deposited directly 

extend well up the slopes of the older metamorphic rocks upon the metamorphic rocks that form the core of the 

which form the axis of the mountain and dip away from mountain and must at one time have formed the bottom 

it toward the north or northeast at the rate of 20° or 30°. and shores of the Miocene sea. The simplest interpretaBeing more resistant to weathering agencies than the soft tion of this relation is to suppose that before that change 

overlying shales, these have been stripped from the sand- of conditions was complete which substituted muddy 

5 0 5 10 l5Miles 

-

Carri~o f'ormat1on 

Andesite 

~ 

m 

Basement 

.complex 

FIGURE 46.-Geologic sketch map of the southwestern part of the Colorado Desert, Cal., north of the Mexican boundary line, showing position of 

the geologic formations. Areas in the valleys represented without formational symbol are occupied by Pleistocene lake beds and alluvium. 

(After Kew.) 

stones at many points so that the old Miocene beach, its brackish . water with oyster colonies for clear sea water 

sands indurated and its teeming life preserved only in and marine life, the sands of the earlier beach had been 

fossil form but yet exhibiting much the aspect and much swept away, so that there is unconformity, without disthe same relations which existed at the time of its deposi- cordance, or at h~ast without marked discordance in dips, 

tion, is revealed for the modern student's inspection. and without a great time interval between the deposition 

These basal sands are not always found where their horizon of the sands and the deposition of the muds. The other 

is exposed. In many places the fine clays that were hypothesis, namely, that these beach sands and the muds 
360 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1916. 

were deposited contemporaneously, because of differing 

local conditions, is made difficult to apply because the 

two physically different terranes overlie the basement 

rocks at very closely adjacent points, with no obvious 

explanation as to why such different conditions should 

have prevailed so near together. 

The heavy sandstones occur at a number of places 

along the north slope of Carrizo Mountain, east of the head 

of Garnet Canyon. Many arroyos are incised in them, 

the stream channel in some cases being a mere notch 

but a few feet wide and 100 or more deep. Fossils, however, have not been reported in numbers except at th~ 

head of Garnet Canyon. 

At the head of Barrett Canyon, which drains south 

from Black Mountain, the same general relations prevail 

that have been described in the area a dozen miles to the 

south; on the slopes of Carrizo Mountain. But the fragments of the basal beds of the Miocene are even more 

widely scattered, and the sandstones and conglomerates 

are not so fully developed. 

About 4! miles above the mouth and one-half mile above 

the forks of the arroyo the basal beds of the Miocene flank 

the qlder rocks and extend across the valley from the 

west fork to the east fork. Dips here are 20°-40° 8.-that 

is, away from the mountain. The beds are not so thick 

as on Carrizo Mountain but are succeeded, as is the case 

there, by soft yellow shales. 

About a mile above this point, in a little cove at the 

head of a small western tributary of -Barrett Creek, other. 

outcrops of basal sandstone and conglomerate, not more 

than 10 feet thick, occur with the underlying igneous 

rocks all about them. Near this outcrop is a fossil coral 

reef lyl.ng upon the lavas and isolated from all the other 

sedimentaries. A half mile farther north a sheet of 

sandstone, folded into a basin and thus somewhat protected from erosion, still exists. Doubtless many other 

similar fragmental exposures would be revealed by more 

extended search. [See Pl. XCIII.] 

The collections of fossil corals were obtained 

from localities numbered 164 and 167, respectively, by Messrs. Mendenhall and Bowers. 

The positions of these localities are platted on 

the map (fig. 43, p. 356). Mendenhall describes 

them as follows: 

Nos. 164 and 166 are from Alverson Canyon and the head 

of Garnet Canyon on the south and north slopes, respectively, of Carrizo [Coyote] Mountain. The horizons are 

identical, being in each case the sandstones which form the 

upper part of the arenaceous series at the base of the 

Miocene. These are the most conspicuous fossil localities 

in the region. The shells or their casts have weathered 

out and strew the slopes in great profusion. Corals, 

echinoids, Ostrea, pectens, Strom bus, and Malea are everywhere. The matrix, however, is coarse and only large and 

robust types are well preserved. The locality has been 

noted by prospectors generally because the occurrences are 

so conspicuous. [Views shown on Pl. XCII.] 

No. 167. This collection consists of corals almost entirely. 

The fossil reef is near the head of Barrett Canyon and lies 

directly upon the igneous rocks which served as a basement for Miocene sedimentation at this point. Whatever 

later beds may have originally covered it have been 

stripped away, so that the old reef is now isolated. [View 

shown on Pl. XCIII.] There can be little doubt, however, 

that its position is at the base of the Miocene series and 

substantially equivalent to that of Nos. 164 and 166. 

No. 164 of Mendenhall and Bowers is entered 

in the United States Geological Survey register 

of localities at which Cenozoic invertebrates 

have been collected as No. 3923; and No. 167 

is entered there as No. 7616. 

The observations recorded in preceding paragraphs show that the reef corals grew up unconformably on a basement during a period of 

submergence that followed a period when the 

basement stood above sea level. These relations of vigorous coral growth to change of 

sea level have been found to prevail in so 

many areas where reef corals thrive that they 

appear to be general. 1 The deposits in which 

the corals are embedded are largely arenaceous,· 

and the reefs ultimately were probably killed 

by burial beneath sediment, as sugg€sted by 

Mendenhall. At the time the reefs flourished 

there was, of course, shallow water in the area 

where their remains are now found, and the 

temperature probably averaged about 21° C. 

(70° F.) during the coldest months of the year.2 

SIGNIFICANCE OF THE CORAL FAUNA. 

GENERIC AFFINITIES OF THE FAUNA OF 

CARRIZO CREEK. 

The discussion of this fauna may be best introduced by placing in parallel columns the 

names of the genera represented on Carrizo 

9I'eek, those of the shoal-water corals known to 

occur along the west coast of Central America 

from the Gulf of California to the Bay of 

Panama, and those of the genera found living 

in shoal water in the Floridian, ... 1\.ntillean, and 

eastern Central American region. The data for 

the column headed "Guaymas to Panama" are 

taken from a paper by Verrill. 3 

1 See Vaughan, T. W., Science, new ser., vol. 41, pp. 508,509, Apr. 2, 

1915; Geol. Soc. America Bull., vol. 26, p. 58, 1915; Vaughan, T. W., and 

Shaw, E. W., Carnegie lnst. Washington Yearbook No. 14, pp. 237, 

238, 1916. 

2 For recent discussions of the ecologic conditions necessary for the 

formation of coral reefs, see Vaughan, T. W., Physical conditions under 

which Paleozoic coral reefs were formed: Geol. Soc. America Bull., vol. 

22, pp. 238-252, 1911; Results of investigations of the ecology of the Floridian and Bahaman shoal-water corals: Nat. Acad. Sci. Proc., vol. 2, 

pp. 95-100, 1916; Temperature of the Florida coral-reef tract: Carnegie 

Inst. Washington Pub. 213, 1917. 

a Verrill, A. E., On the geogr~hical distribution of the polyps of the 

west coast of America: Connecticut Acad. Arts and Sci. Trans., vol. 1, 

pp. 562, 563, 1870. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 98 PLATE XCIII 

A. THE BARRETT CANYON FOSSIL CORAL REEF. 

The reef is shown in the right middle ground. At this locality the corals rest directly upon the effusive roc ks, 

which rise higher and form the surrounding hi lls. 

B. VIEW OF FOSSIL CORAL LOCALITY NEAR HEAD OF BARRETT CANYON. 

The basal beds of the Pliocene sandstones overlie effusive rocks and dip to the right in the foreground of t he view. The coral reef lies immediately upon the effusive rocks. Coyote Mountain in the background. 

VIEWS oF BARRETT CANYON. IMPERIAL CouNTY. CAL. 

Photographs and explanations by W. C. Mendenhall. 

REEF-CORAL FAUNA OF CAR.RIZO CREEK, IMPERIAL COUNTY, CAL. 361 

Coral genera represented at Carrizo Creek, Cal., and on the 

west and east sides of Central America. 

Genu2. Carrizo 

Creek. 

Caribbean 

Guaymas and Mexto 

Panama. ican Gulf 

region. 

Paracyathus........... . . . . . . . . . . X X 

Pocillopora. . . . . . . . . . . . . . . . . . . . . . X ......... . 

~~fi~~~ ~ .·. ~ ~ : : : : : : : : : :I: : : : : : : : : : : : : : : : : : : : 

Stephanocrenia ........................... . Eusmilia.... . . . . . . . . . . . X ......... . Dichocrenia. . . . . . . . . . . . X ......... . Meandrina ................................ . Dendrogyra ............................... . Astrangia... . . . . . . . . . . . . . . . . . . . . . . X 

Phyllangia... . . . . . . . . . . . . . . . . . . . . X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

Ulangia. . . . . . . . . . . . . . . . . . . . . . . . . X .........• Cladocora ................................ . Orbicella .................................. . Solenastrea. . . . . . . . . . . . X ......... . Favia .................. , ................... . Mrea??-ra.............. X ... -... -.. Man1c1na .................................. . Mussa s. s ................................. . Mussa (Isophyllia) ........................ . Mussa (Acanthastrea) ...................... . Mycetophyllia ............................ . 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

!~::r1~i~·-- _· ~: : : : : : : : : : : : : : : : : : : : : : .... ~ .... --.. x. --- Pavona................ .......... X 

Stephanaria.. . . . . . . . . . . . . . . . . . . . . X ......... . Siderastrea. . . . . . . . . . . . X ......... . X 

Dendrophyllia.......... . . . . . . . . . . X 

Astropsammia.. . . . . . . . . . . . . . . . . . . X 

Rhizopsammia.................... X ......... . Acropora ............................ _ .. __ . _ X 

Montipora. . . . . . . . . . . . . . . . . . . . . . . X 

Porites................ X X X 

Total (33 genera). 6 13 24 

Six genera are included in the fauna of 

Carrizo Creek, only one of which (Porites) is 

at present known to occur on the west coast 

of America, though all six are found in the 

Gulf of Mexico and the Carib bean Sea. Of 

13 shoal-water genera at present represented 

by species on the west coast of Central 

America, only 4 are represented on the east 

coast. One of the remaining 9 genera (Dendrophyllia) is found in the western Atlantic 

in water over 50 fathoms deep, but any similarity suggested by its presence may be offset 

by the fact that it is essentially worldwide in 

distribution. The genus Endopachys occurs in 

water 39 fathoms deep in the Gulf of California 

but is unknown in the West Indian and 

Floridian area. The table lists 24 West Indian 

genera, 4 of which also occur on the west side 

of Central America. The number 24 might be 

somewhat increased, as Verrill has described 

a species of Cyphastrea from the Bahamas/ 

under the name Oyphastrea nodulosa, and I have 

in my possession an undescribed species of 

Oulophyllia from the Bahamas, sent to me by 

Miss A. M. Boynton, __ of Nassau. The Oulophyllia is strikingly similar to 0. bonhourei 

Gravier,2 from French Somaliland. Both 

Cyphastrea and Oulophyllia are widely distributed in the Indo-Pacific, but they are not 

known to occur along the Pacific coast of 

Central America. Two West Indian shoalwater genera, Oculina and Cladocora, occur in 

deeper water off the Pacific coast. 

The table shows the IJ;l;arked difference between the coral faunas on. the two sides of { 

Central America and indicates that the affinities of the fauna of Carrizo Creek are with the 

fauna of the Mexican Gulf and Caribbean area. 

Have the faunas on the two sides of Central 

America always been so distinct? An attempt 

is made to answer this question in the following discussion. 

GEOLOGIC HISTORY OF THE CORAL FAUNAS OF 

THE SOUTHEASTERN UNITED STATES AND 

THE WEST INDIES. 

EOCENE AND LOWER OLIGOCENE FA UN AS. 

The data presented in the following table 

are largely taken from my monograph on the 

Eocene and lower Oligocene coral faunas of 

the United States,3 revised so as ,to represent 

the present stage of knowledge. 

Geographic distribution of Recent genera of corals found also 

in the Eocene and lower Oligocene deposits of the southern 

United States. 

Genus. 

Flabellum ... . .. . Sphenotrochus .. 

Platytrochus ... . Turbinolia ...... . Trochocyathus .. 

Paracyathus ..... 

Caryophyllia .... 

Distribution. 

Almost universal. 

Mediterranean Sea and North Africa, 

coast of Brazil, European coasts of 

north Atlantic Ocean, South Australian coast. 

Australian seas (?). 

Caribbean Sea, Indo-Pacific. 

West Indies, South American seas, 

Indo-Pacific. 

Mediterranean Sea, Caribbean Sea, 

north Atlantic Ocean, Indian Ocean, 

Pacific Ocean, California (Pearl Islands). 

Littoral and deep sea, very general. 

1 Verrill, A. E., Connecticut Acad. Arts and Sci. Trans., vol. 11, p. 107, 

pl. 31, figs. 2, 2a, 2b, 1902. 

2 Gravier, Charles, Inst. oceanogr. Annales, fasc. 3, p. 49, pl. 4, figs. 25, 

26; pl. 5, figs. 27, 28, 1911. 

aU. S. Geol. Survey Mon. 39, pp. 33, 34, 1900. 
362 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1916. 

Geographic distribution of Recent genera of corals found also 

in the Eocene and lower Oligocene deposits of the southern 

United States-Continued. · 

Genus. 

Oculina ....... . 

Madrepora ..... . 

Stylophora .... . Madracis ....... . 

Parasmilia ..... . Astrangia ...... . 

Dichocamia ... . Siderastrea ..... . 

Balanophyllia .. 

Eupsammia .... . Endopachys .... . Dendrophyllia .. 

Goniopora ...... . 

Distribution. 

Florida, Caribbean Sea, Bermudas, 

Indian Ocean, Pacific Ocean. 

Atlantic Ocean, Caribbean Sea, Mediterranean Sea, Indo-Pacific. 

Red Sea, Indo-Pacific. 

Madeira, Florida, Caribbean Sea, Brazil, Adriatic Sea, Indo-Pacific. 

Caribbean Sea, Philippines. 

Florida, Central America, East Indies, 

Panama Bay, east and west coasts of 

North America, Strait of Magellan. 

West Indies. 

Caribbean Sea, islands off west coast of 

Africa, Indo-Pacific. 

Caribbean Sea, Mediterranean Sea, 

English Channel, St. Helena, Madeira, 

California, Indo-Pacific. 

Chinese seas. West coast of America, Pacific. Caribbea~ Sea, Atlantic Ocean, Cape 

Verde, Madeira,. Mediterranean Sea, 

Bay of :Panama, California, IndoPacific. 

Indo-Pacific. 

The foregoing table shows that in their 

generic relations the Eocene and lower Oligocene corals of the southeastern United States 

are about equally divided between the Atlantic 

and the Indo-Pacific regions. There is a great 

resemblance between the species of Paracyathus, Balanophyllia, and Siderastrea now found 

in the West Indian region and the Eocene 

species of the same genera; but Platytrochus, 

Styloph,ora, Eupsammia, Endopachys, and Goniopora are not represented by known species 

from the Atlantic Ocean. 

The difference between the Eocene faunas 

of the southern United States and the Eocene 

fauna of the West Indies is striking, as no 

known species is common to the two regions. 

The difference is probably due to two causes. 

One is climatic; the area in the United States 

lay so far north that except during early Midway and Vicksburg time it was not within the 

zone of truly tropical conditions. During 

Wilcox and Claiborne time and the earlier part 

of Jackson time the sea was warm-temperate 

but not actually tropical. For this reason 

reef corals did not abound in the southern 

United States during the Eocene epoch except 

in early Midway time.· In the Jackson epoch 

there was a gradual recurrence of tropical conditions and during lower Oligocene time a 

well-developed coral reef, composed of species 

of Stylophora and Goniopora was formed at 

Salt Mountain, Ala. The other cause of faunal 

difference lies in the difference in stratigraphic 

history, as the known Eocene deposits of the 

West Indies include representatives of only the · 

upper groups of the series. Because according 

to present knowledge the Antilles contain no 

Eocene deposits stratigraphically corresponding 

to the Midway, Wilcox, and probably Claiborne 

groups of the United States, they are supposed 

to have stood above sea level during the period 

of deposition of these groups. 

There is a fairly rich Eocene coral fauna on 

the Island of St. Bartholomew and a scantier 

fauna is known from Jamaica. The principal 

literature on these faunas is cited below.1 

The determination of the Eocene age of the 

St. Bartholomew coralliferous deposits is based 

on evidence of several kinds. ·A part of the 

evidence consists in my discovery in association with the coral fauna of a stellate orbitoidal 

foraminifer, closely resembling in general 

aspect a species I found in 1900 on Flint 

River near Bainbridge, Ga. Dr. Joseph A. 

Cushman has studied both the St. Bartholomew 

and the Flint River specimens and informs me 

that they belong to the genus Orthophragmina, which is considered to indicate positively 

an Eocene age. 

In 1904 Prof. A. G. Hogbom, of the University of Upsala, sent to me for study the 

entire collection obtained on St. Bartholomew 

by Prof. Cleve,2 and during February, 1914, I 

spent eight days studying and collecting on the 

island.3 The following list of genera is based 

upon both these collections, and I have added 

the names of four genera represented in Jamaica 

(the names followed by· "J" in the table) but 

not known in St. Bartholomew. 

1 Cleve, P. T., On the geology of the northeastern West India Islands: 

K. svenska Vet.·Akad. Handl., vol. 9, No. 12, p. 24, 1872. 

Hill, R. T., The geology and physical geography of Jamaica: Harvard 

Coll. Mus. Comp. Zool. Bull., vol. 34, pp. 123-137, 1879. 

Vaughan, T. W., Some Cretaceous and Eocene corals from Jamaica: 

Harvard Coll. Mus. Comp. Zool. Bull., vol. 34, pp. 227-256, pls. 36-41, 1899; 

Study of the stratigraphic geology * * * of thb smaller West Indian 

Islands: Carnegie Inst. Washington Yearbook No. 13, pp. 358-360, 1915; 

[Present status of the geologic correlation of the Cretaceous and Tertiary formations of the Antilles]: Washington Acad. Sci. Jour., vol. 5, p. 489, 1915; 

Study of the stratigraphic geology * * * of the smaller West Indian 

Islands: Carnegie.Inst. Washington Yearbook No. 14, pp. 368-373, 1916. 

2 P. M. Duncan's report on this collection was published in London Geol. 

Soc. Quart. Jour., vol. 29, pp. 548-565, pls. 19-22, 1873. 

a A minor grant from the Carnegie Institution of Washington enablEld 

me to do geologic field work and make extensive collections in Antigua 

St. Bartholomew, and Anguilla during February and March, 1914. The 

discussion of the fossil corals of these islands herein presented is based 

largely on the collections made at that time. 
REEF-CORAL FAUNA OF CARRIZO CREEK, IMPERIAL COUNTY, CAL. 363 

Corals in the upper Eocenu of St. Bartholomew and Jamaica. extinct. Although further study may add to 

the list, its essential indications will not be 

Genus. ~~~~~-c J:c1~~ Extinct. changed. The upper Eocene fauna of St. 

Bartholomew contains representatives of 11 

0 Placotrochus................ . . . . . . . . X 0 Asterosmili.a. .. . . . . .. .. . . . .. X ............... . 0 Trochosmilia. . . . . .. .. . .. . .. . . . .. .. . .. .. . . . . X 0 Stylophora ............. ..... -.... --- X 0 Astrocrenla. . . . . . . . . . . . . . . . . X ... -- - - - -. -.... - 0 Antillia ................... - . . . . . .. . X 

°Favia....................... X X 0Goniastrea. . . . . . . . . . . . . . . . . . . . . . . . . X 0Mreandra. . . . . . . . . . . . . . . . . . . X X 

Leptoria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . X 0 Syzygophyllia............... . .. .. .. . X 

Trochoseris (J) ............. _ ................ . 

Mesomorpha (J) ............................ . Antilloseris . . . . . . . . . . . . . . . . . . _ . . . . . . . . ...... . Physoseris .. .. ....... ................ _ ...... . Protethmos a. . . . . . . . . . . . . . . . . . . . . . . . . . ...... . 

Metethmos a .•.. ..... ........................ 0 Actinacis ........... ....................... . Dendracis (J) ................................ . 

Multicolumnastrrea (J) ....................... . 0 Goniopora. .. .. . .. .. . .. .. .. . . .. .. .. . X 

Total (21 genera) ..... . 4 9 

X 

X 

X 

X 

X 

X 

X 

X 

X 

10 

a These two genera were described by Gregory (Paheontologia indica, 

9thser., vol. 2, pt.; P.J?-162-167, 1900) from specimens obtained in the 

Jurassic of Cutch, md1a, and appear to be represented in the Eocene 

of St. Bartholomew, but the generic identifications are not beyond question. 

Of the 21 genera named in the table 4 are 

represented to-day in the Atlantic Ocean, 2 of 

them only in the Atlantic; 9 are represented 

in the living Pacific fauna, 7 of them only in 

the Pacific; and 10 genera are so far as known 

living genera of corals, and 7 of these are, 

according to our present knowledge, now confined to the Indo-Pacific region. Therefore its 

affinities are more · with the Indo-Pacific fauna 

of to-day than with that of the Atlantic. 

The genera whose names are preceded by 

a degree mark (

0 ) also occur in deposits of 

Oligocene age. 

UPPER. OLIGOCENE FAUNAS. 

Although there is much similarity in the 

upper Oligocene faunas, there are at least four 

recognizable horizons at which they occur in 

the southeastern United States. These are, 

named in stratigraphically ascending order, as 

follows: (1) Basal part of the Chattahoochee formation, in the reefs near Bainbridge, Ga.; (2) the 

silex bed of the Tampa formation, near Tampa, 

Fla., and at numerous localities in Florida and 

southern Georgia; (3) the Chipola marl member of the Alum Bluff formation; (4) the Oak 

Grove sand member of the ·Alum Bluff formation. Although the descriptions of these 

faunas are not quite complete, their essential 

characteristics have been ascertained. The 

following is a list of the coral genera: 

Coral genera represented in the upper Oligocene deposits of Georgia and Florida. 

Genus. 

Basal 

Chatta.-.. 

hoochee. 

Silex bed, Chipola 

Tampa. marl. 

Oak 

Grove Atlantic. Pacific. Extinct. 

sand. 

Astrhelia ...... , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . X 

Stylophora . . . . . . . . . . . . . . . . . . . . . . . . X X X . . . . . . . . . . . . . . . . . . . . X . . ....... . Stylocrenia....................... X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X 

Astrocrenia. . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . ........ . Antillia. . . . . . . . . . . . . . . . . . . . . . . . . . X X X . . . . . . . . . . . . . . . . . . . . X ......... . Orbicella............. . . . . . . . . . . . . . X X . . . . . . . . . . . . . . . . . . . . X X ......... . Solenastrea....................... . . . . . . . . . . . . X -......... . . . . . . . . . . X X ......... . Galaxea.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ......... . Favites.................. . ....... X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ......... . Mreandra..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . X X ......... . Newgenus........... . ............ .......... .. ............ X .......... .... . ..... .......... X 

Syzygophyllia..................... ....... . .... (?) .......... .......... .......... X ......... . S1derastrea. : . . . . . . . . . . . . . . . . . . . . . X X . . . . . . . . . . . . . . . . . . . . X X ......... . Mesomorpha . . . . . . . . . . . . . . . . . . . . . X ........... . ....... . ..... . ... ... ................. _ . . X 

Diploastrea............. . . . . . . . . . . . X ...................... __ ... _ . . . . . . . . . . . . . . X ......... . Endopachys... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ......... . Acropora............. ......................... X .......... .......... ~< X ......... . Actinacis. .... . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X 

Astreopora...... . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ......... . Porites ......................... - - ...... - . . . . . X . . . . . . . . . . . . . . . . . . . . X X ...... . -. . Goniopora.. . . . . . . . . . . . . . . . . . . . . . . X X X . . . . . . . . . . . . . . . . . . . . X ......... . Alveopora..... . . . . . . . . . . . . . . . . . . . X X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ......... . 

Total (22 genera) .......... . 13 13 4 1 7 16 5 
364 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1916. 

Of 13 genera represented in the basal Chattahoochee, 2 occur in the living faunas of both the 

Atlantic and the Indo-Pacific, 7 occur only in 

the Indo-Pacific, 1 only in the Atlantic, and 3 

are extinct. The silex bed of Tampa contains 

13 genera, 7 of which are at present confined to 

the Indo-Pacific, 6 are common to the Atlantic 

and Indo-Pacific, and none is extinct. The 

Chipola marl contains 4 genera, 3 of which 

persist in the Indo-Pacific but are not known 

in the Atlantic, and 1 is extinct. Only 1 

genus, Astrhelia, has been found in the Oak 

Grove sand. It is represented in the lower 

Miocene of Maryland, but is now extinct. 

Tropical marine temperatures ·prevailed as 

far north as southern Georgia throughout the 

deposition of the Chattahoochee and Tampa 

formations, but during the period when the 

upper beds of the Alum Bluff formation were 

being laid down the waters cooled and living 

upper Oligocene coral reefs vanished from 

Georgia and Florida. The cooler Miocene 

epoch followed, and it was succeeded by the 

warm Pliocene epoch, during which reef corals 

flourished in southern Florida, but, as will 

later be DJ!tl,de clear, they represent a different 

fauna, for during the Miocene every coral of 

Pacific facies had disappeared, and the Pliocene 

fauna is of purely Atlantic affinities. 

The West Indian and · Central American 

upper Oligocene faunas represent several different horizons. (See references to my papers, 

p. 362.) One of the faunas, that at the base of 

the ''marl formation,,. of Antigua (the Antigua 

formation of J. W. Spencer), is almost identical 

with that at the base of the Chattahoochee 

formation near Bainbridge, Ga. Beds representing the same horizon are exposed 4 miles 

west of Lares, Porto Rico; and beds representing the same or nearly the same horizon occur 

at the base of the bluff at Crocus Bay, on the 

north side of the island · of Anguilla. The 

higher beds in the Crocus Bay exposures seem 

to correspond stratigraphically with the Emperador limestone of Panama. The fauna of 

Bowden, Jamaica, is nearly related to this 

higher fauna but may be somewhat younger. 

The following t·abl.e presents the list of genera 

for Antigua, Anguilla, Empire (Panama), and 

Bowden (,Jamaica). 

Genera of corals in the upper Oligocene of Antigua, Anguil:'la, Empire (Panama), and Bowden (Jamaica). 

[Genera whose names are followed by (L) occur also 4 miles wait of Lares, Porto Rico.] 

Genus. Antigua. Anguilla. PEmpire, anama. Bowden, 

Jamaica. Atlantic. Pacific. Extinct. 

Placocyathus... ....................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . (?) ....... __ . Placotrochus.......................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . X ......... . Sphenotrochus... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X X X ......... . Trochosmilia........................... X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X 

Asterosmilia.......................... X ................ ·.... X X ................... . Stylophora............................ X X X X .. .. .. .. .. X ........ .. Pocillopora.. . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ......... . 

~lJ~~is~~::: ~ ~: : : : :: : ~ : : : : : : : : : : : : :: .... ~ ........ ~ .... ::: : : : : : : : .... x ........ x ........ x. . . . . ... ~ ... . . Astrocrenia (L) .................... :. . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ................... . Antillia ........ ·. . . . . . . . . . . . . . . . . . . . . . X X . . . . . . . . . . X . . . . . . . . . . X ......... . Orbicella(L) ......................... X X X .......... X X ........ .. Cladocora. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _. . . . . . . . . X . . . . . . . . . . . . . . . . . . . . X X .........• Diplothecastrea..................... . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X 

Favites... . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ......... . Goniastrea............ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . X ......... . Lamellastrooa........ .... ... . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X 

Thysanus...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . X 

Teleiophyllia.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . x Mooa;n~ra (L) .......................... X . . . . . . . . . . . . . . . . . . . . . . . . . . . ... X X ......... . Man1c1na.............................. X . . . . . . . . . . . . . . . . . . . . . . . . . ..... X ................... . Syzygophyllia.......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . X ......... . Agaricia (L) ... .... .................... . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . X ................... . Pavona........ . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . X ......... . New genus. . . . . . . . . . . . . . . . . . . . . . . . . . . X X _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X 

Leptoseris. . . . . . . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ......... . Haloseris ...... ·. . . . . . . . . . . . . . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X ......... . Siderastrea (L) ....................... X X .. .. .. .. .. X X X ........ .. Diploastrea .......... _... . . . . . . . . . . . . . . . X ................... , . . . . . . . . . . . . . . . . . . . . X ......... . . Acropora.............................. X .......... . X X X X ......... . · Astreopora (L) ..................... .-. X . . . . . . . . . . X . . . . . . . . . . . . . . . . . . . . X ......... . Porites.................. .. .. . .. . .. .. . X X X X X X ......... . Goniopora (L) . . . . . . . . . . . . . . . . . . . . . . . . . X X X X . . . . . . . . . . X .... . .... . 

Alveop;:~~i(~~-~~~~;~)~~~~~~~~~:::::: ~ ----~~--------·;--------~~--------~;---· ] 22~?1 ..... 7 ... .. 
REEF-CORAL FAUNA OF CARRIZ.O CREEK, IMPERIAL COUNTY, CAL. 365 

The Antiguan fauna contains 24 genera, of 

which only 5 are extinct; of the 19 genera represented by living i,;pecies 2 are now confined 

to the Atlantic, 5 are represented in both the 

Atlantic and Pacific, and 12 (50 per cent) are 

at present confined to the Pacific. The fauna is 

predominantly Pacific. Of the 9 genera on 

Anguilla 3 are at present confined to the Pacific. 

Of the 8 genera from Empire, Panama, 5 are represented by living species only in the Pacific . . Of 

the 14 genera represented at Bowden, Jamaica, 

2 are extinct, 2 are at present confined to the 

Atlantic, 5 are common to the Atlantic and 

Pacific, and 6 (if Placocyathus is included) are 

confined to the Pacific. Stephanocamia is 

found at Bowden and appears to have been 

collected in place. It is also Pleistocene and 

Recent in the West Indies. The livingStephanocmnia inter septa (Esper) is the type of the 

genus. 

Because of the known presence of species of 

Lepidocyclina (identified by J. A. Cushman) in 

the base of the Chattahoochee formation near 

Bainbridge, Ga., in the Antigua formation in Alutigua, in the fossil reefs of Anguilla, and in the 

Emperador limestone of Panama, most paleontologists will agree as to the Oligocene age of 

these deposits, and as the beds exposed 4 mil~s 

west of Lares, Porto Rico (the Pepino formation of Hill) contain essentially the same coral 

fauna as the Antigua form:ttion, their Oligocene 

age will probably be conceded. 

It should be stated here that H. Douville 1 

refers Lepidocyclina canellei Lemoine and R. 

Douville and L. chaperi Lemoine and R. Douville, both of which occur in the Culebra formation of the Canal Zone, to the Aquitanian, 

which he considers to be Miocene. The Culebra 

formation immediately underlies the Emperador limestone, in which the principal reef-coral 

fauna of the Canal Zone is found in association 

with Lepidocyclina and other orbitoidal Foraminifera. The larger Foraminifera of the Canal 

Zone are described in a paper, now awaiting 

publication, by Dr. Jos. A. Cushman, who has 

almost completed descriptions of the species of 

Lepidocyclina and Orthophragmina from the 

southeastern United States and the West 

Indies. 

Regarding the age of the formations belonging 

to the Apalachicola group but higher than the 

1 Les orbitoi:des de l'ile de Trinite: Paris Acad. sci. Compt. rend., vol. 

161, pp. 87-92, 1915; Les couches a orbitoi:des de l'isthme de Panama.: 

Soc. geol. France Compt. rend. for Dec. 20, 1915, pp. 129-130. 

Chattahoochee formation in Georgia and Florida 

there is controversy, and the controversy extends to the age of the marl at Bowd~n, Jamaica, some paleontologists contending that 

these formations are of Oligocene age, others 

that they are of Miocene age. Berry 2 has 

recently discussed this subject, and his concluding remarks are as follows: 

There is thue no structural (diastrophic) evidence for 

drawing the Oligocene-Miocene boundary between the 

Chattahoochee and Alum Bluff formations, nor is there 

any floral or faunal evidence for such a boundary. There 

is such a break between the Vicksburg and Apalachicola 

groups, and the Alum Bluff is separated by an erosion 

unconformity from the overlying Choctawhatchee Miocene. It rests with inTertebrate paleontology to determine whether or not the whole of the Apalachicola group 

shall be considered Miocene. Whatever may be the final 

verdict, it remad.ns true that the flora preserved at Alum 

Bluff records the last phase of sedimentation before the area 

emerged from the sea and that the most profound break in 

Tertiary sedimentation in the southeastern United States, 

emphasized equally by epeirogenic; :"'faunal, and floral 

changes, was at the end of Apalachicola time-that is, it 

is represented by the unconformity at the top of the Alum 

Bluff formation. 

Tke Apalachicola group has an impressive 

unity for those who have had extensive field 

experience in studying it, and they will not 

readily sanction its dismemberment. Out of 

13 genera, the Bowden marl oontains 6 of IndoPacific affinities (Placocyathus, Pla~otrochus, 

Stylophora, Antillia, Syzygophyllia, and Goniopora) and 2 (Thysanus and Teleiophyllia) that 

are extinct. As the affinities of thi~ coral fauna 

are predominantly Indo-Pacific, I am inclined 

to the opinion that it corresponds stratigraphically to the upper part of the Apalachicola 

group and is older than the Chesapeake group 

(Miocene) of the United States. 

Apalachicolan time was terminated by the 

notable geologic events mentioned in the quotation from Berry.3 These events led to a 

severing of the waters of the Atlantic from 

those of the Pacific by the establishment of 

land connection between North and South 

America. It seems that the extinction of the 

coral genera of purely Pacific affinities was 

effected by causes not understood but in some 

way related to these events, for these genera 

2 Be.rry, E. W., The physical conditions and age indicated by the 

flora of the Alum Bluff formation: U. S. Geol. Survey Prof. Paper 98, 

pp. 44-46, 1916 (Prof. Paper 98-E). 

a For additional discussion of the subject see Vaughan. T. W ., A contribution to the geologic history of the Flocidian Plateau: Carnegie Inst. 

Washington Pub. 133,' pp. 153-157, 1910; Vaughan, T. W., and Cooke, 

C. W., Correlation of the Hawthorn formation: Washington Acad. Sci. 

Jour., vol. 4, pp. 250-253, 1914. 
366 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1916. 

are not present In the next younger important 

eoral fauna of the southeastern United States. 

MIOCENE FAUNA. 

The Miocene coral fauna of the eastern and 

southeastern United States Is poor both in 

genera and in species.1 The genera are Paracyathus, Astrhelia, Astrangia, Septastrea, and 

a species described by Gregory 2 under the 

name Prionastrrea vaughani, which perhaps 

should be referred to the genus Favites-a 

total of five genera. The marine waters of the 

Miocene in the southeastern United States, as 

Dall and others have pointed out, were cold as 

compared with the earlier Apalachicola and the 

later Pliocene sea, and Berry 3 has recently reconsidered this subject. Although the waters 

appear not to have been so cold as was formerly believed, they were too cold for reef corals, 

and such organisms disappeared from the eastern and southern parts of the continent during 

Miocene time. 

PLIOCENE FAUNA. 

Pliocene time was initiated by a recurrence 

of warm-water conditions, and with the change 

in climate a fairly rich reef-coral fauna established itself in Florida as far north as latitude 

27°. It is especially well exposed within the 

area underlain by the Caloosahatchee marl. 

The following are the genera: 

Corals in the Caloosahatchee marl (Pliocene). 

Carrizo 

Genus. Atlantic. Pacific. Creek, 

Cal. 

Oculina ............... X X ................... Dichocrenia ........... X .................... X 

Meandrina .............. X ...................... ................ .. .. Phyllangia ............ X X ..................... Solenastrea ............. X X X 

Septastrea (extinct). ~hysanus (extinct). Mreandra ............... X X X 

Siderastrea ..... . ....... X X X 

Porites ........... . ..... X X X 

Total (10 genera). 8 6 5 

1 See Vaughan, T. W., Maryland Gcol. Survey, Mi.ocene, pp. 438-447, 

pls. 122-129, 1904. 

2 Gregory, J. W ., New species of Cladophyllia, Prionastrrea, and Stylina: Annals and Mag. Nat. Hist., 7th ser., vol. 4, p. 458, figs. 2a, 2b, 1899. 

3 Berry, E . W ., The physical conditions indicated by the flora of the 

C!llvert formation: U. S. Geol. Survey Prof. Paper 98, pp. 61-73, 1916 

(Prof. Paper 98-F). 

The foregoing table shows that of 10 genera 

represented in the Caloosahatchee marl 2 are 

extinct, 8 persist in the living Antillean fauna, 

and 6' are common to the Atlantic and the 

Indo-Pacific. The species belonging to the 8 

genera that are also Recent are either living 

or, with one exception, so near species at present living on the Florida and Bahama reefs 

that specific discrimination is difficult or doubtful. All the purely Indo-Pacific elements are 

lacking in this fauna, which, except for one of 

the two extinct genera (Septastrea) is typically 

Antillean. Of the 6 genera represented in the 

fauna of Carrizo Creek 5 also occur in the 

Caloosahatchee fauna, and all 6 are present in 

the living Antillean fauna. 

PLEISTOCENE AND RECENT FAUNAS. 

A list of the genera of corals at present 

living in the shoal waters of the West Indies, 

Florida, and Central America is given on page 

361. Until now it has not been possible to 

distinguish between the Pleistocene and Recent 

faunas of the region, as all definitely identified 

Pleistocene species are also found living in the 

same regiOn. 

SUMMARY. 

The data presented in the foregoing discussion show: 

1. Thttt during Eocene, lower Oligocene, and 

upper Oligocene time the coral faunas of the 

southeastern United States and the West . 

Indies comprised three elements-(a) genera 

now extinct; (b) RecBnt genera which are now 

living only in the Indo-Pacific region; and (c) 

genera which persist in the western Atlantic 

Ocean, the Gulf of Mexico, and the Caribbean 

Sea, and some of which are also present in the 

living Indo-Pacific faunas. 

2. That the sharp differentiation between 

the Atlantic and Pacific faunas took place 

between the end of Apalachicola time and the 

beginning of Pliocene time, and that since 

Pliocene time there has been only subordinate 

modification of the Atlantic fauna. 4 

4 R. A. Daly's suggestion that this differentiation was due to lowering 

of marine temperature during Pleistocene glaciation (Am. Acad. Arts 

and Sci. Proc., vol. 5, pp. 169-170, 1915) can not be true, for the differentiation had taken place before Pliocene time. 
REEF-CORAL FAUNA OF CARRIZO CREEK, IMPERIAL COUNTY, CAL. 367 

3. That this differentiation was in some way 

related to diastrophic and other geologic 

events which occurred during Miocene time. 

The causes of the extinction of the Pacific 

elements are unknown. The problem is rendered more difficult because the reef corft.ls of 

the Atlantic and Indo-Pacific conform to the 

same ecologic principles.1 Mayer says in his 

paper on Torres Straits: "We must conclude 

that 'corals are corals,' and their behavior is 

essentially alike both in Florida and Australia.'' 

4. That the systematic affinities of the fauna 

of Carrizo Creek are with the Caloosahatchee 

Pliocene of Florida and the Pleistocene and 

living faunas of the Antilles. 

GEOLOGIC AGE OF THE FAUNA OF CARRIZO 

CREEK. 

From statements already made it is obvious 

that there has been great uncertainty as to 

the geologic age of the fauna of Carrizo Creek. 

At first it was thought to be probably Cretaceous, later it was considered lower Miocene, 

after that it was referred to the upper Miocene, 

and the .latest opinion is that it is Pliocene. 

The following statement and list are quoted 

from Kew: 2 

The age of the Carrizo formation 3 has not been definitely 

determined. Dr. Arnold 4 referred to it as equivalent to 

the upper Miocene or lower Pliocene Etchegoin formation 

of the San Joaquin Valley of middle California, correlating 

by means of the pectens. The echinoderm fauna seems to 

indicate a comparatively late age, as several of the forms 

are very closely related to the species living in the Gulf 

of California at the present time, and these species are presumed to change relatively rapidly. Whether this seemingly slow development is due to comparative isolation in 

a warm-water area is as yet not known. These questions 

can not be answered definitely until the fauna has been 

compared carefully with the Recent life from the Gulf of 

California. 

1 See references to my papers on p. 360. Also Mayer, A. G., An expedition to the coral reefs of Torres Straits: Pop. Sci. Monthly, vol. 85, pp. 

209-231, 1914; Ecology of the Murray Island coral reef: Nat. Acad. Sci. 

Proc., vol. 1, pp. 211-214, 1915; Carnegie Inst. Washington Pub. 213, 

pp. 1 et seq., 1917. 

2 Kew, W. S. 'V., Tertiary echinoids of the Carrizo Creek region, in the 

Colorado Desert: California Univ. Dept. Geology Bull., vol. 8, pp. 46, 

47, 1914. 

a See footnote on p. 355. 

4 Science, new ser., vol. 19, p . 503, 1904; U.S. Geol. Survey Prof. Paper 

47, p. 21, 1906; U.S. Geol. Survey Bull. 396, p. 44, 1909. 

An approximate list of the fauna of the Carrizo formation, 

so far as determined, is as follows: 

PELECYPODA . 

Anomia sub costa Conrad .... Anomia n. sp ______________ --

Area n. sp. A ............. _ Area n. sp. B _ .. _ .. __ ...... . Cardium aff. C. quadrigenarium Conrad ............ . Crassatellites sp ... . . _ ..... . Divaricata eburnea Reeve .. . Dosinia n. sp ...... . . _ .... _ .. Glycymeris sp ............. . Hinnitesgigantea n. var. ... . Lithodomus sp .. . .... _. _ ... . Hetis alta Conrad ..... _ .. _ . _ Ostrea heermani Conrad .... . Ostrea vespertina Conrad ... . Panope generosa Gould ._ ._ .. Pecten carrizoensis Arnold .. Pecten subnodosus n. var. _. Pecten circularis n. var _ ... . Pecten deserti Conrad ..... . Pecten cerrosensls var. men- denhalli Arnold. _____ .. _ .. Pecten keepi Arnold __ . _ . _ .. Pecten n. sp ......... __ . _ . _ Phacoides cf. P. sanct::ecrucis Arnold __ . _ . _ ... ______ . 

Pinna sp ............. . ... . . . Pholas sp .... _ ... _ . . ___ . _ .. 

GASTROPODA . 

Architectonica sp. _. ____ .... Cancellaria sp. A. ______ ._ .. Cancellaria sp. B . . .. ___ ... _ Cassis sp ............... ___ . _ Cerithium sp .. _.: .. _ .. ___ . _ Conus sp. A._ ........ __ ___ _ 

Conus sp. B ............... _ Dolium cf. D. ringens Sowerby ..................... . Neverita cf. N. recluziana Petit~ .... _ ......... _ ... . Oliva cf. 0. porphyria Lin- n::eus ................... . Pleurotoma n. sp .......... . Terebrasp. A ...... . ....... . Terebra sp. B .............. . Turritella n . sp ... __ .. __ .. _. _ 

ECHINODERMATA. 

Encope tennis n. sp ........ . Cidaris sp ................. . Clypeaster bowersi Weaver_. 

Clypeaster carrizoensis n. sp. 

Clypeaster deserti n . sp ..... . Hipponoe californica n. sp .. 

1 

Lower Upper diviBion. 

division, 1----:------

all Carrizo Y uha lo~alities . Valley. Buttes. 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X X 

X X 

X 

X X 

X 

X X 

X 
368 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1916. 

Regarding the echinoids Kew 1 says that 

" Olypeaster bowersi Weaver resen1bles Echinanthv..s ( Olypeaster ~) testudinarius Gray, living in 

the Gulf of California," and that "The Recent 

Hipponoe depressa A. Agassiz found in the Gulf 

of California and on the west coast of Lower 

California is closely allied to Hipponoe californica.'' 

N omland 2 refers the coralliferous beds on 

Carrizo Creek to the Pliocene, and he says in a 

letter to me dated June 13, 1916: 

In regard to the Pliocene age of the Carrizo Creek beds 

there is only very little evidence. Dr. Arnold correlated 

the Etchegoin 3 with the CaiTizo Creek beds and thought. 

Edwards and Haime. I am confident t.hat 

the species does not belong to Madrepora. 

The specific affinities of the Carrizo Creek 

corals are discussed in detail after the descriptions in the systematic part of this paper. The 

Carrizo Creek species are so near species belonging to the same genera in the Pliocene 

Caloosahatchee marl of Florida and in the 

Pleistocene and living reefs of Florida and 

West Indies that it seems to me they can 

scarcely. be so old as Miocene; lower Pliocene 

appears to be the maximum age which may 

be assigned to the fauna. 

Corals from Carrizo Creek, Cal. 

Name. Most nearly related species in Florida or West Indies. a 

Eusmilia carrizensis Vaughan, n. sp...................... Eusmilia fastigiata (Pallas), PI, R. 

Dichocoonia merriami (Vaughan) ......................... }Dichocce:riia sp., P; D. stokesi Milne Edwards and Haime, var. crassisepta Vaughan, n. var...................... PI, R. 

Siderastrea fairbanksi (Vaughan), typical. ................ } var. columnarls (Vaughan) ........................... Solenastrea hyades (Dana) and S. bournoni Milne Ed- var. normalis Vaughan, n. var....................... wards and Haime, P, PI, R. var. minor Vaughan, n. var .......................... . M~andra bowersi Vaughan, n. sp ......................... M~andra labyrinthiformis (Linnreus), PI, R. 

Siderastrea. mendenhalli Vaughan, n. sp ....... -... -.- · ·- ·. }siderastrea sp., P. var. ID.lnor Vaughan, n. var ........................ . Siderastrea californica Vaughan, n. sp..................... Siderastrea sp., P. 

Porites carrizensis Vaughan, n. sp ....................... Porites astreoides Lamarck, PI, R. 

a P, Pliocene; Pl, Pleistocene; R, Recent. 

both of Miocene age. His correlation was based almost BEARING OF THE FAUNA OF CARRIZO CREEK ON 

entirely on Pecten deserti Conrad. Later we found, M A POSSmLE POST-OLIGOCENE INTEROCEANIC 

shown by land vertebrates, that the Etchegoin formation 

and, as we thought, also the Carrizo Creek beds are of 

Pliocene age. I have recently collected from the Etchegoin a large number of specimens of the form called 

Pecten deserti by Arnold. I find, however, that this is 

undoubtedly different from the species occurring in the 

Carrizo Creek beds. The Pelecypoda and Gastropoda 

which have heretofore been specifically listed may be 

either Miocene or Pliocene. 

In addition to the ~pecies and varieties listed 

in the accompanying table N omland describes 

and figures a coral from Carrizo Creek under the 

name Madripora salida. I have not seen this 

species and am not sure as to its generic relations. I suppose "Madripora" is intended to 

be Madrepora, type species Madrepora oculata 

Linnams = .Amphelia oculata (Linnreus) Milne 

1 Kew, W. S. W., op. cit., pp. 50, 51. 

2 Nornland, J. 0., Corals from the Cretaceous and Tertiary of Cali· 

fornia and Oregon: California Univ. Dept. Geology Bull., vol. 9, p. 

60, 1916. 

a Arnold, Ralph, Paleontology of the Coalinga district, Fresno and 

Kings counties, Cal.: U. S. Geol. Survey Bull. 396, p. 44, 1909. 

CONNECTION. 

That there was interoceanic connection 

across parts of Central America during upper 

Oligocene time and that this connection was 

terminated in Miocene time is generally admitted. The extinction of facific faunal elements in the Gulf of Mexico, the Caribbean 

Sea, and the western Atlantic Ocean has been 

discussed and summarized on page 366. Was 

there interoceanic connection during upper 

Miocene or Pliocene time after the sharp differentiation of the Caribbean and Mexican 

Gulf faunas from the Indo-Pacific faunas, 

thereby permitting interoceanic faunal migration~ The discovery of a reef-coral fauna of 

purely Floridian and Caribbean facies at the 

head of the Gulf of California strongly suggests; 

if it is not positive proof, that the western 

Atlantic fauna extended from the Atlantic into 

the Pacific after the faunal differentiation had 
REEF-CORAL FAUNA OF CARRIZO CREEK, IMPERIAL COUNTY, CAL. 369 

taken placa. It is well known that the living 

reef-coral fauna on the Pacific side of Central 

America is depauperate in comparison with 

that on the Atlantic side. Greater vigor may 

account for the dominance of the migrant 

fauna over the Pacific fauna, which was finally 

suppressed, or geologic or other ecologic conditions that are not yet understood may have 

excluded the Pacific fauna from the head of the 

Gulf of California, while they permitted the 

migration of the Atlantic fauna into that area. 

oceanic connection, which permitted the Atlantic fauna to extend into the Gulf of California and up to its head, and conditions not 

yet understood excluded the Pacific fauna 

from the area. 

7. The locus of the inferred interoceanic connection is not known. It was probably in the 

region of the Isthmus of Tehuantepec, or farther southeast. 

SYSTEMATIC DISCUSSION OF THE FAUNA. 

MADREPORARIA IMPERFORATA. 

Family EUSMILIIDlE Verrill. 

That the suggested interoceanic connection 

existed can scarcely be doubted. To locate 

it, in the present state of meager knowledge of 

the areal and stratigraphic geology of Central 

America, is not possible. Perhaps it was Genus EUSMILIA Milne Edwards and Haime. 

across the Isthmus of Tehuantepec. The 1848. Eusmilia Milne Edwards and Haime, Compt. Rend., 

problem awaits future investigation. vol. 27, p. 467. 

Type species: Madreporajastigiata Pallas. 

CONCLUSIONS. 

The foregoing discussion may be summarized 

as follows: 

1. The Carrizo Creek reef-coral fauna is 

Atlantic, not Pacific, in its affinities. 

2. During Eocene and Oligocene time there 

was connection between the Atlantic and 

Pacific oceans across Central America, and 

there was no sharp differentiation between the 

Atlantic and Pacific faunas. 

3. Upper Oligocene (Apalachicolan) time 

was closed by diastrophic and other geologic 

events of profound importance, which separated the Atlantic from the Pacific Ocean by 

forming a land area extending from North to 

South America. During Miocene time sharp 

differentiation between the Atlantic and Pacific 

faunas took place, largely by the extinction of 

the Pacific elements in the Atlantic area. 

4. The Pliocene coral fauna of Florida is 

purely Atlantic in its affinities, and since 

Pliocene time there has been only minor modification of the coral fauna in the western 

Atlantic, the Gulf of Mexico, and the Caribbean Sea. 

5. The fauna of Carrizo Creek is related to 

Pliocene and post-Pliocene faunas of Florida 

and the West Indies and can scarcely be older 

than lower Pliocene. 

6. Subsequent to the differentiation between 

the Atlantic and the Pacific faunas there was 

in upper Miocene or Pliocene time interEusrnilia carrizensis Vaughan, n. sp. 

Plate XCV, figures 1, 1a. 

Corallum cespitose, similar in growth form 

to Eusmilia fastigiata. Single branches as 

much as 13.5 by 15 millimeters in diameter. 

Costre distinct but not very prominent, alternately larger and smaller, corresponding to the 

septa. 

In a small corallite 8.5 millimeters in diameter there are about 16 septa which extend 

to the columella; alternating with these are 

shorter and much thinner septa. In places 

three smaller septa may be seen in a loculus 

between two large septa. In a space 5.5 millirneters long, measured on a chord. there are 7 

septa. 

Columella trabecular, well developed. 

Locality: Barrett Canyon, Carrizo Creek. 

Imperial County, Cal. 

Affinities: This species is about as close to 

Eusmilia fastigiata (Pallas), of the Floridian 

and Antillean region, as Dichocmnia merriami 

is to D. stokesi. The difference between the two 

is that E. fastigiata has more crowded septa, 

about ten in 5.5 millimeters, wherea~ E. carrizensis has seven in the same space. The 

growth form, the size of the branches, and the 

eolumellar character are the same in both. 

Illustrations of E. fastigiata are g1ven on 

Pia te XCV, figures 2., 2a. 
370 SNORTER 'CONTRIBUTIONS TO GENERAL GEOLOGY, 1916. 

Genus DICHOC<ENIA Milne Edwards and Haime. 

1848. Dichocamia UilnEi! E<iwards and Haime, Compt. 

Rend., vol. 27, p. 469. 

1857. Dichocrenia Milne Edwards and Haime, Histoire 

naturelle des coralliaires, vol. 2, p. 199 (type 

specieefigured, Pl. DI, figs. lOa, lOb). 

Type species: .Astrea porcata Lamarck, on authority 

of Milne Edwards and Haime. 

It is my belief that Madrepora porcata Esper 1 

is not this species, for Esper says: "Die FHiche 

ist ganz eben, und die Sterne ohne einen erhoheten Rand zu haben, eingesenkt." His figures suggest a coral similar to Favia puteoli'lU]; 

(Dana) or Favia dance Verrill. The Dichocmnia porcata of Milne Ed wards and Haime 

differs from D . . stokesi principally by the possession of an "epitheque extremement mince 

et peu distihcte." It seems to me probable 

that their D. porcata and D. stokesi -are the 

same species, especially as I have never seen a 

specin1en of a living species of Dichocrenia 

from the Pacific or Indian Ocean, and none are 

reported by Studer, Stanley Gardiner, Bedot, 

Von Marenzeller, Gravier, or Matthai. According to the present available information, the 

genus is found living only in the western Atlantic Ocean, the Gulf of Mexico, and the 

Caribbean Sea. The Dichocmnia uva of Milne 

Edwards and Haime is based on Esper's Madrepora uva,2 from the China Sea. This appears 

to be a species of Favia and is probably the 

same as Fa'IYia speciosa (Dana). From the description, it seems to me that Dichocmnia stellaris Milne Ed wards and Haime is a varietal 

form of D. stokesi. A positive opinion can be 

based only upon a restudy of Milne Edwards 

and Haime's original specimens and types, but 

the suggestion is warranted that their D. porcata, D. stokesi, and D. stellaris all belong to the 

same species, and that both Madrepora porcata and M. uva of Esper belong to the genus 

Favia and not to Dichocrenia. 

Dichocrenia merriami (Vaughan) Vaughan. 

Plate XCIV, figures 1, la. 

1900. Favia merriami Vaughan, U. S. Geol. Survey Uon. 

39, p. 142, pl. 15, figs. 5, 5a-5c. 

1906. Favia merriami Vaughan, in Arnold, Tertiary and 

Quaternary pectens of California: U.S. Geol. Survey Prof. Paper 47, p. 22. 

1916. Favia merriami Nomland, California Univ. Dept. 

Geology Bull., vol. 9, p. 60. 

I Esper, E. J. C., Fortsetzungen der Pflanzenthiere, pl. 71, 1795. 

s Idem, pl. 43. 

The origin:\l description of this species is as 

follows: 

Corallum snbplane or rounded above, massive. The 

species is based on three broken specimens, nearly of a 

size. * * * The condition of preservation of the material i5, as is unfortunately too often the case with the 

fossil species, not :satisfactory. The calices are elliptical. 

The following gives measurements of several: 

1 2 3 4 

------

Mm. Mm. Mm. Mm. 

Greater diameter of ealice ..... 6.5 6. 5 5.5 5. 5 

Lesser diameter of calice ..... 4~5 2. 5 4.5 4.5 

Some calices are almost circular, with a diameter of 4.5 

millimeters. The calices are from 2 to 3 millimeters apart. 

The walls between the corallites are thick (2 to 3 millimeters) and usually compact; are evidently formed of 

fused costre; correspondingly, sometimes the costre can in 

the sections be traced some distance across the area between 

the corallites. On the upper surface of the corallum costre 

correspond to all septa and extend from one calice to the 

next. They are low, sometimes flattened above or slightly 

acute, minutely granulated, straight or somewhat flexuous. Septa, in calice No. 1 of the above table, about 33 in 

number. The number for the fully grown calices seems 

to vary between 30 and 36; younger calices may have only 

24. The various cycles are not distinctly indicated. 

There is usually a fairly regular alternation in size of the 

septa, the larger ones reaching the columella. They are 

thick, thicker at the wall, and have paliform thickenings 

on their inner ends. Faces granulate. Dissepiments very 

well developed, thin, 1.5 to 2.5 millimeters apart in the 

longitudinal section of the corallites. The character of the 

septal margins is not shown by the material at hand. The 

calicular fossre are extremely shallow or are almost superficial. The columella is false, large, well developed. 

The large suite of specimens collected by 

Mendenhall and Bowers makes a fuller description of the species possible. 

The corallum ·is of massive growth form, 

upper surface regularly domed or undulate. 

The following are the dimensions of four 

specrmens: 

Dimensions of Dichocamia merriami, in millimeters. 

u.i u.i ~ a;> a;> a;> • 

-~ -~ ~,.:s 

~- ~ ~ ·~ ~ c.> c.> . ........ (!) 

..d 0 0 o.;:: 

-:5 ~ ...; ..c:: ..c:: ,..Q;::::: "0 

~ ~ 

bO ~ bO ~ ~~ 

~ a;> ~ "0 "ljl-+ 

a;> ;..., a;> a;> 

~ ·~ 0 

H I=Q ~ H ~c.> 

--

1 ......... 133 107 76 6-17 3.5-6 1-4 

2a ........ 151 111 97 5. 5-13 3.5-6. 5 1-3 

3 ......... 147 116 85 5.5-10 4-5. 5 1-5 

4 ... ······ 147 121 83 4. 5-12. 5 3-7 1-4 

a Upper surface with humps. 
REEF-GORAL FAUNA OF CARRIZO CREEK, IMPERIAL COUNTY, CAL. 371 

The size of the calices is given in the table. 

The shortest calices have been recently cut off 

by fission from the parent corailite and are subcircular or elliptical in form. In the longest 

calices there are usually three centers which 

have not been isolated by complete fission. 

The distance apart ranges from the thickness 

of a dividing septum to about 5 millimeters. 

The least width of the corallite wall a~ given 

in the table is for calices which are completely 

separated and have developed intercorallite 

walls. 

The calicular edges are somewhat elevated, 

the outer surface of the corallites sloping or 

falling almost perpendicularly to the bottom 

of the intercorallite depressions. The maximum amount of exsertness on these specimens 

is about 1 millimeter. Costre correspond to 

the septa but usually are not notably prominent. 

The septa and columella are better shown in 

the specimen represented by Plate XCIV, 

figures 1, 1 a, described below. 

Corallum subhemispherical, 57 by 67 millimeters in diameter and 39 millimeters tall. 

Corallites project as much as 2.5 millimeters; 

distance between calicular margins from 1 to 

3 millimeters; free limbs with distinct subequal or slightly alternating costre that correspond to all septa. Length of calices frmn 5 

to 13.5 millimeters; width from 3 to 6.5 m.illimeters. Septa in a young corallite 4 m.illimeters in diameter about 18, of which 8 reach 

the columella; in a corallite 5.5 by 8.5 m.illimeters in diameter, there are 43 septa, of 

which 12 are appreciably larger than the others 

and reach the columella, and 8 others are 

nearly as large; alternating with the 20 larger 

septa are smaller septa, and there are a few 

rudimentaries. Another corallite 10.5 Inillimeters long has 42 septa, of which about half 

reach the columella, and there is an equal 

number of smaller septa. In places three sizes 

of septa are recognizable, and here and there 

are septal groups of threes. Septal margins 

apparently entire; paliform lobes commonly 

present. Septal faces granulate. 

Columella trabecular, well developed; in 

some elongate calices an axial lamella is present, but this is derived from a septum. 

Locality: Barrett Canyon, Carrizo Creek, 

Imperial County, Cal. 

Affinities: This species is very close to Dichocmnia stokesi Milne Edwards and Haime, which 

is found on the living reefs in the Bahamas, 

the West Indies, and Florida, and occurs fossil 

in Santo Domingo, where it has been known as 

Barysmilia intermedia and Dichocmnia tuberosa, 

both proposed by Duncan. 1 A closely related 

species is found in the Pliocene Caloosahatchee 

marl of Florida, but descriptions and figures of 

it have not been published. There are in tha 

United States National Museum large suites of 

D. stokesi. In growth form, general aspect, the 

size and distribution of the calices, and the 

character of its costre it is like D. merriami, 

but the columella of D~ stokesi seems to be less 

well developed, and a calice 4.5 by 7 millimeters in diameter has 42 septa, one 5 millimeters in diameter has 34 septa, and one 4 

millimeters in diameter has 24 septa. Therefore D. stokesi seems to have a weaker columella and somewhat more numerous septa than 

D. 1Yierriami, but the differences are so slight 

that the California specimens should perhaps 

be referred to the same species as the one to 

which the Floridian and West Indian specimens belong. To facilitate comparison· of the 

two species, figures of D. stokesi are given in 

Plate XCIV, figures 2, 2a. 

Dichocrenia merriami var. crassisepta Vaughan, n. var. 

Plate XCIV, figures 3, 3a. 

This variant has thick, strongly exsert principal septa with corresponding strong costre 

and thin intermediate septa with corresponding thin costre. The differential characters are 

shown in the figures. 

Locality: Barrett Canyon, Carrizo Creek, 

Imperial County, Cal. 

Family ORBICELLIDlE Vaughan. 

Genus SOLENASTREA Milne Edwards and Haime. 

1848. Solenastrea Milne Edwards and Haime, Compt. 

Rend., vol. 27, p. 494. 

1850. Solenastrea Milne Edwards and 'Haime, British 

fossil corals, Introduction, p. xl. 

Type species: Astrea turonensis Michelin. 

The following is the characterization of the 

genus published by Milne Edwards and Haime 

in 1850: 

Corallum forming in general a convex mass, of a light 

and cell-ular structure. Gemmation extra calicular. Co1 London Geol. Soc. Quart. Jour., vol. 19, pp. 431, 432, 1863. 
372 SHORTER CONT'RIBUTIONS TO GENERAL GEOLOGY, 1916. 

rallites long, slender, and united by an exothecal structure, and not by costre, which do not meet and are often 

rudimentary. Calices circular, with an exsert margin. 

Columella spongy, and in general small. Septa very thin; 

their margin denticulated. Dissepiments simple, numerous, and closely set. 

Solenastrea and Cyphastrea were united by 

Duncan under the former name, the latter 

being reduced to subgeneric rank, 1 and characterized as follows: ''The gen~ric characters 

are as in Solenastrea, but the septa are cribriform." 

Leptastrea, Solenastrea, Cyphastrea and 

Orbicella are closely related genera. The following paragraphs indicate what seem to me 

to be the differential characters. 

Leptastrea Milne Edwards and Haime (type 

species, L. roissyana Milne Edwards and 

Hair~~), septa impe~orate, corallites usually 

not ]Olned by costre, 1ntercorallite tissue compact, its surface more or less granulate but not 

spinulose. 

Solenastrea Milne Edwards and Haime (type 

species, Astrea turonensis Michelin), similar to 

Leptastrea, except that the corallites are separated by highly vesicular exotheca, unless 

crowded, when they may be separated by 

simple walls, 

Cyphastrea Milne EdwardB and Haime (type 

~pecies, Astrea microphthalma Lamarck), simIlar to Solenastrea, except that the inner parts 

of many septa are cribriform, and the surface of 

the intercorallite tissue is spinulose. 

Orbicella Dana (type species, Madrepora 

annularis Ellis and Solander), similar to Cyphastrea, except that the costre are strongly 

developed and extend from one corallite to 

another. 

I have been perplexed and have vacillated 

in my treatment of Solenastrea, sometimes re-

. ferring it to the synonymy of Cyphastrea, some-

~imes to th~t of Orbicella. I am now retaining 

It as a vahd genus for the following reasons: 

There is a group of species which is represented in the Recent and fossil faunas of Florida 

and the West Indies, and which shows constant 

characters. The group is well represented in 

the Tampa upper Oligocene, in the Caloosahatchee Pliocene, and in both the Pleistocene 

and living faunas. Except where the corallites are greatly crowded, they are separated 

by highly vesicular intercorallite tissue, the 

Linnean Soc. London Jour., vol. 18, p. 107, 1884. 

upper surface of which is granulate and ~ore 

or less costate but not spinulose. The castre 

may or may not extend from one corallite to 

the next; if the corallites are close together 

they may meet, but if the corall.tites are distant 

they usually do not meet. The costre where 

well developed have not along their summits 

dentations, as in Orbicella, nor small sharp 

spinules, as in Cyphastrea. Because of the 

constant differences between this group of 

species and other genera, and of the constant 

similarity within the group, apparently it 

should have generic recognition. 

Unfortunately no specimens of the type 

species of Solenastrea are available to me for 

study; but to judge from Michelin's very good 

figures and from the description of Milne 

Edwards and Haime the foregoing statement 

applies to the characters of the genotype. 

There are two species in the living West 

Indian fauna, both of which also occur in the 

Caloosahatchee Pliocene. One is Solenastrea 

hyades (Dana) (see Pl. XCVIII, all figures), 

which appears to be a synonym of Madrepora 

pleiades Ellis and Solander, and Solenastrea 

bournoni Milne-Edwards and Haime (see Pls. 

XCIX and C, all figures), of which the following species of Duchassaing and Michelotti are 

synonyms: Heliastrcea abdita, Leptastrcea caribcea, Cyphastrcea carpinetti, Solenastrcea micans, 

and Solenastrcea ellisi. InS. hyades the members of the third cycle of septa fuse to the 

sides of the secondaries; in S. bournoni the . 

inner ends c;>f the tertiaries are free. 

Solenastrea fairbanksi (Vaughan) Vaughan, typical. 

Plate XCV, figures 3, 3a. 

1900. Stephanocmnia jairbanksi Vaughan, U. S. Geol. 

Survey Mon. 39, p. 151, pl. 17, figs.ll, lla. 

1906. Plesiastrea californica (nomen nudum) and Stephanocmnia jairbanksi Vaughan, in Arnold, Tertiary 

and Quaternary pectens of California: U.S. Geol. 

Survey Prof. Paper 47, p. 22 . 

1916. Stephanocmnia jm.rbanksi Nomland, California 

Univ .. Dept. Geology Bull., vol. 9, p . 60. 

The original description of this species is in 

part as follows: 

Form of corallum explanate or columnar . . The speci-

~ens possessing the explanate method of growth may be 

considered the typical form; those with the columnar 

method of growth, S. jairbanksi var. columnaris var. nov. 

* * * The corallites are polygonal in 'form, usually 

hexagonal, and are joined directly by their walls or by 

very short costre. The greater diameter of the corallites 
REEF-CORAL FAUNA OF CARRIZO CREEK, IMPERIAL COUNTY, CAL. 373 

is very constantly 3.5 millimeters. Some corallites may be 

smaller and some slightly larger, but 3.5 millimeters is the 

usual diameter. The walls between two corallites on an 

unweathered surface or in a section are stout and usually 

solid; they are almost a millimeter thick. They are clearly 

pseudothecal. In places the corallites may be joined by 

very short costre; then open vertical spaces may exist between the costre. None of the specimens shows the upper 

edge of the wall in its original condition; therefore its ornamentation can not be described. The septa are in three 

complete cycles; the members of the first and second cycle 

fuse to the columella; those of the third cycle fuse to the 

sides of those of the second (?). (There is no way of 

differentiating the first from the second cycle.) They 

are thicker at the wall; their faces granulate. The character of the septal margins could not be studied. In the bestpreserved calices there appear to · be pali before both the 

first and second cycles of septa. In the thin section both 

of these cycles of septa show thickenings on and near their 

inner ends corresponding in positjon to the apparent lobes 

on the septa. The calices are not preserved intact, but 

that 12 pali existed seems quite clear. Endotheca very 

well developed. 

The original description needs modification 

in only one particular. The excellent suite of 

specimens obtained by Mendenhall and Bowers 

shows that the columella is trabecular and is 

not like that of the type species of Stephanocmnia ( .Madrepora inter septa Esper). The tertiary septa may or may not fuse to the sides of 

the secondaries; in the same calices some of 

the tertiaries are fused to the secondaries, and 

others have free inner ,margins. 

Solooastrea fairbanksi var. columnaris (Vaughan) 

Vaughan. 

Plate XCVI, figures 1, la. 

1900 . . Stephanocceniajairbanksi var. columnaris Vaughan, 

U. S. Geol. Survey Mon. 39, p. 151, pl. 17, figs. 

10, lOa. 

1906. Stephanocceniajairbanksi var. columnaris Vaughan, 

in Arnold, Tertiary and Quaternary pectens of 

California: U. S. Geol. Survey Prof. Paper 47, 

p. 22. 

1916. Stephanoccenia jm:rbanksi var. columnaris Nomland, California Univ. Dept. Geology Bull., vol. 

9, p. 60. 

This variety differs from the typical form of 

the species in its columnar growth form and 

on the average its wider intercorallite areas. 

Both eharacters are shown in the figures. 

Locality: Barrett Canyon, Carrizo Creek, 

Imperial County, Cal. 

Solenastrea fairbanksi var. normalis Vaughan, n. var. 

Plate XCVI, figures 2, 2a, 2b, 2c; Plate XCVII, figures 1,, la. 

Most of the specimens of this variety are 

more or less hemispherical in form, and some 

attain a height of over 320 Inillimeters. The 

calicular characters are similar to those of the 

type specimen, except that the calicular 

margins are free, are slightly elevated, and 

may be as much as 2 millimeters apart. The 

costre are distinct just below the calicular 

margins and may or may not meet on the 

intercorallite areas. 

The range in diameter of the calices is from 

2.5 to 3.5 miUimeter.s, and the usual diameter 

is about 3 millimeters. This variety is discriminated from variety minor solely by its 

somewhat larger calices. 

Localities: Alverson and Barrett canyons, 

Carrizo Creek, Imperial County, Cal. 

Solenastrea fairbanksi var. minor Vaughan, n. var. 

Plate XCVII, figures 2, 2a, 2b, 2c. 

This variety differs from var. normalis by 

its smaller calices, which range from 1.5 to 

2 millimeters in diameter. The inner ends of 

the tertiary septa are usually but not invariably 

free. 

Locality: Alverson Canyon, Carrizo Creek, 

Imperial County, Cal. · 

Affinities of Solenastrea fairbanksi. 

As often happens when a new species is based 

on a single specimen, or only a few specimens, the 

type specimen of this species does not represent 

the usual character of the speeies. The type has 

an explana te mode of growth and crowded calices 

separated by narrow walls. Plate XCV, figure 

3, represents a typical specimen, one-half nat:.. 

ural size, It is a pulvinate mass, 185 millimeters 

in diameter, and 68 millimeters thick. Plate 

XCV, figure 3a, represents a group of calices, enlarged four times. Specimens such as this might 

be considered to represent a species distinct from 

those later described as the varieties normalis 

and minor, were not intergradation completely 

shown. Plate ·xcv, figures 4, 4a, gives two 

views of two ealicular areas, each enlarged four 

times, on the same specimen, to show variation 

in the intercorallite walls. It appears that 

flattish colonies have crowded calices and that 

more or less hemispherical colonies have more 

distant calices. The illustrations of Solenastrea fairbanksi 

Canyon, Carrizo Creek, (Pl. XCV, figs. 3, 3a, 4, 4a; Pl. XCVI, all 

figures; and Pl. XCVII, all figures) may be 

Locality: Alverson 

Imperial County, Cal. 
374 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1916, 

compared with those of Solenastrea hyades 

(Dana) ( Pl. XCVIII, all figures), from the 

Pliocene Caloosahatchee marl of Florida, and 

with those of Solenastrea bournoni Milne 

Edwards and Haime (P1s. XCIX and C, all 

figures), which is now living in the We~t Indies 

and is a common species in the Caloosahatchee 

marl in Florida. Although these seem to be 

three well-marked species they are all closely 

related. The only species at present living in 

the Pacific which seems to me to belong systematically near this group of species is the coral 

from Wake Island to which Dana applied the 

name Astrcea (Orbi,cella) pleiades and which 

was subsequently referred to So~enastrea by 

Verrill. (Dana's original specimen is No. 56, 

U. S; National Museum.) The Carrizo Creek 

specimens seem to me more closely related to 

the West Indian and Floridian specimens than 

to the form from Wake Island. 

Family FA VllD.l:E Gregory. 

Genus M.l:EANDRA Oken. 

1815. Mreandra Oken, Lehrbuch der Naturgeschiclite, 

Theil 3, Abt. 1, p . 70. 

1902. Mreandra Verrill, Connecticut Acad. Arts and Sci. 

Trans., vol. 11, p. 66. 

Type species: Madrepora labyrinthiformis Linnreus. 

Mreandra bowersi Vaughan, ~· sp. 

Plate CI, figures 1, 1a. 

1906. Diploria bowersi (nomen nudum) Vaughan, in Arnold, 

Quaternary pectens of California: U. S. Geol. 

Survey Prof. Paper 47, p. 22. 

Corallum massive, subhemispherical. Type 

is a piece of a specimen whose diameter is 

about 70 millimeters; thickness about 37 millimeters. 

Valleys relatively long and sinuous, 27 millimeters a common length; one exceeds 40 

millimeters. A few circumscribed calices; one 

of these is about 6.5 millimeters in diameter. 

Width of valleys from 3. 75 to 5.5 millimeters; 

usually about 4 millimeters; depth about 2 

millimeters. Interserial colline with a shallow 

median depression; width of colline from 1. 75 

to 3}5 millimeters, usually 2.5 to 3 millimeters. 

Costre well developed, correspond to all septa, 

distant, edges acute. 

Septa, about 8 large ones, which reach the 

columella, to 1 centimeter; intermediate rudimentary septa variable in development, present 

in some places, absent in others. 

Columella false, trabecular, fairly well developed. 

Locality: Carrizo Creek, Imperial County, 

Cal. Stephen Bowers, collector. 

Affinities: This species resembles },freandra 

(" Diploria ") labyrinthiformis, of Florida and 

the Antilles, but as the latter has about 12 

principal septa to the centimeter, the two species 

can readily be distinguished. Plate CI, figure 2, 

presents a view of the valleys and collines of 

M. Zabyrinthiformis, twice natural size. The only 

known living species of Mreandra closely related 

to M. bowersi are in the West Indies, none at all 

being known in the modern Indo-Pacific faunas. 

MADREPORARIA FUNGIDA. 

Family AGARICITD.l:E Verrill. 

Genus SIDERASTREA De Blainville. 

1830. Siderastrea De Blainville, Dictionnaire des sciences naturelles, vol. 60, p. 75. 

Type species: Madrepora galaxea Ellis and Solander, 1786=Madrepora radians Pallas, 1766. 

Siderastrea mendenhalli Vaughan, n. sp. 

Plate CI, figures 3, 3a, 4. 

The corallum is massive in form and has a 

flattish, rounded, or undulate upper surface. 

Some colonies attained a large size, as one 

specimen, not here described in detail, is 425 

millimeters tall and over 440 millimeters in 

diameter on its upper surface. 

Calices regularly polygonal or usually more 

or less deformed; diameter from 4 to 7 millimeters in those regularly polygonal; greater 

diameter of deformed calices as much as 7 millimeters; shorter diameter, from about 2.5 to 4 

millimeters. The calicular cavities are rather 

shallow, the septal margins sloping gently from 

the narrow intercorallite wall to the bottom of 

the fossa. 

Septa rather thin, crowded, usually in four 

complete cycles, the higher cycles grouped 

around the secondaries and tertiaries, as is 

usual in the genus. In many small calices the 

fourth cycle is incomplete in some systems; 

in large calices there are many members of the 

1ifth cycle. Septal dentations rather fine, 13 or 

more on the large septa; about 15 dentations 

were counted on a septum 2 millimeters long. 

Synapticulre highly developed, extending more 

than halfway from the wall to the columella; 

as many as 10 were counted between the wall 

and the columella in one interseptal loculus. 
REEF-CORAL FAUNA OF CARRIZO CREEK, IMPERIAL COUNTY, CAL. 375 

Columella rather small, false; upper surface 

finely papillate. 

Localities: Alverson and Barrett canyons, 

Carrizo Creek, Imperial County, Cal. 

Affinities: This species belongs to the same 

group as Siderastrea siderea (Ellis and Solander), 

which is one of the common corals on the living 

reefs of Florida and the West Indies, but S. 

siderea has deeper, rather funnel-shaped calices. 

S. mendenhalli is close to a species found in 

the Caloosahatchee Pliocene of Florida but not 

yet described in print. 

Siderastrea mendenhalli var. minor Vaughan, n. var. 

Plate en, figure 1. 

This variant is separated from the typical 

examples of the species by -the smaller average 

size of its calices. There is intergradation, as 

the largest calices of the variant are 4 millimeters in diameter, but most of them are 3 

millimeters or less in diameter. The fourth 

cycle of septa is usually incomplete in some of 

the systems. 

Locality: Barrett Canyon, Carrizo Creek, 

Imperial County, Cal. 

Siderastrea californica Vaughan, n. sp. 

Plate en, figures 2, 2a, 3, 4. 

1906. Siderastrea calijornica (nomen nudum) Vaughan, 

in Arnold, Tertiary and Quaternary pectens of 

California: U. S. Geol. Survey Prof. Paper 47, 

p. 22. 

Corallun1 of massive growth form; upper 

surface flattish or rounded. The largest specimen is 75 by 93 millimeters in diameter, and 105 

millimeters tall. 

Calices polygonal, not greatly deformed. 

Diameter of a large, fully grown one 4.5 millimeters; usual diameter of adult calices 4 millimeters; young calices 2.5 millimeters or less 

in diameter. Walls rather thick. Calicular 

cavities shallow, or superficial. 

Septa relatively thick, especially the six 

primaries and either two or four secondaries. 

There are three complete cycles, and in many 

specimens the fourth cycle is complete in four 

of the six systems but not developed in two 

systems, one on each side of a primary. The 

septal trabeculffi are coarse and produce about 

10 dentations on a primary septum. As there 

are fewer septal trabeculffi there are correspondingly fewer and coarser synapticulffi than 

in S. mendenhalli. 

Cohamella false, papillary; becomes secondarily compacted so that it projects as a stout 

style in weathered calices. 

Localities: Carrizo Creek (type, Stephen 

Bowers collector); Barrett Canyon, Carrizo 

Creek, Imperial County, Cal. 

Affinities: This species can be readily distinguished from S. mendenhalli, if the material is 

well preserved, by its fewer, thicker, and more 

coarsely dentate septa. It is very close to an 

undescribed species from the Caloosahatchee 

Pliocene and is nearS. radians (Pallas), which 

is widely distributed in the Pleistocene and 

.Recent reef areas of the western Atlantic 

Ocean and the Caribbean Sea. Both Siderastrea mendenhalli and S. californica are represented by closely related, very similar, parallel 

species in the Pliocene Caloosahatchee marl of 

Florida. The septa of one of the Florida 

species are composed of small trabeculffi, 

which produce finely dentate septal margins 

and crowded, small synapticulffi, as inS. mendenhalli. The septa of the other species are 

composed of relatively coarse trabeculffi, and 

therefore the septal dentations are coarse and 

the synapticulffi are large, as in S. californica. 

Living species of Siderastrea occur in the Philippine Islands, the Indian Ocean, and the Red 

Sea, but the closest relatives of the Carrizo 

Creek species are in the Caloosahatchee Pliocene of Florida. 

MADREPORARIA PERFORATA. 

Family PORITIDlE Dana. 

Genus PORITES Link. 

1807. Porites Link, Beschreibungen der N aturaliens Sammlungen, Rostock, p. 162. 

Type species: Madrepora porites Pallas. 

Podtes carrizensis Vaughan, n. sp. 

Plate en, figures 5, 5a, 5b, 6, 6a. 

Corallum of nodular or subhemispherical 

form with small gibbosities on its surface. The 

holotype is 62.5 by 71 millimeters in diameter 

and 49 millimeters thick; upper surface flattish. 

Calices polygonal, small, 1.4 to 1. 7 millimeters 

in diameter; excavated, but only moderately 

deep. Separating wall interrupted, zigzag, 

with coarse mural denticles. Its upper edge 

may be acute, or in places where the outer 

margins of the septa are wide it may be flat-
376 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1916. 

tish, with a slight d<!welopment of intercorallite 

reticulum, which is as much a:s 1 millimeter 

across. 

Septa rather thick, 12 in number, arranged 

according to the pori tid scheme; there is a solitary directive, four lateral pairs, and a directive 

triplet. The inner ends of the triplet are more 

or less free; as a rule the laterals of the group 

do not pronouncedly bend toward the included 

directive, but in some calices they seem to join 

it. In places there are suggestions of tr:i.dent 

formation. There is some indefiniteness in the 

lateral pairs. 

In places the septa are narrow in their upper 

parts; usually they are relatively wide over the 

wall, where their upper margins are flattened, 

while their inner margins fall steeply to the 

bottom of the calicular fossa. Normally there 

is a single, somewhat detach~d, rather coarse 

septal granule between the wall and the palar 

ring. The specimens show a fairly well developed outer synapticular ring, and the palar 

synapticular ring is usually complete. There 

is no conspicuous thickening of the horizontal 

structures, the skeletal elements being predominantly radial in the septa, and concentric 

in the wall and in the synapticular rings within 

the calices. 

Pali are fairly well developed but appear 

variable in number, from 4 to 6. 

There is a weak columellar tubercle in so~e 

calices, but if it was present it has heen broken 

in most of them. 

Locality: Barrett Canyon, Carrizo Creek, 

Imperial County, Cal. 

Affinities: Thi~ species has the same growth 

form, the same sized calices, the same mural 

characters, and the same kind of septal margins 

as P. astreoides Lamarck, of Florida and the 

West Indies. There is also a similar indefiniteness in' the septal grouping of each species. 

The calices of P. carrizensis seem shallower and 

the pali better developed than in P. astreoides, 

but the two are remarkably alike. 
PLATES XCIV-CII. 

377 
PLATE XCIV. 

Page. 

FIGURES 1, la. Dichocamia merriami (Vaughan) Vaughan from Carrizo Creek, Cal •... _ ...................... " 370 

1. Corallum, natural size. 

la. Calices, X 3. 

FIGURES 2, 2a. Dichocmnia stokesi Milne Edwards and Hai.me. A recent specimen from Hog Island, Bahamas.. 371 

2. Corallum, natural size. 

2a. Calices, X 3. 

FIGURES 3, 3a. Dichocmnia merriami var. crassisepta Vaughan, n. var., from Carrizo Creek, Cal. ....... _ .. _.___ 371 

3. Corallum, natural size. 

3a. Calices, X 3. 

378 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 98 PLATE XCIV 

sa X3 3 

REEF CORALS. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 98 PLATE XCV 

REEF CORALS. 
l)LATE XCV. 

Page. 

FIGURES 1, 1a. Eusmilia carrizensis Vaughan, n. sp., from Carrizo Creek, Cal. ........... . ........ ............. 369 

1. Corallum, natural size. 

1a. Calicular ends of branches, X 2. 

FIGURES 2, 2a; Eusmilia fastigiata (Pallas), the type species of the genus, from Cocoanut Point, east side of 

Andros Island, Bahamas......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 

2. Corallum, natural size. 

2a. Calices, X 2. 

FIGURES 3, 3a. Solenastrea fairbanksi (Vaughan), typical, from Carrizo Creek, Cal............................ 372 

3, 3a. Two views of a specimen typical of the species; 3, upper surface of corallum, one-half natural size; 

3a, calices, X 4. 

FIGURES 4, 4a. Two views, each X 4, of the calices of a specimen whose calicular characters are between those 

exhibited by typical specimens of Solenastrea fairbanksi and those of var. normalis. (See Pl. XCVI, figs. 

2-2c, and Pl. XCVII, figs. 1, la)......................................................................... 373 

30830°-17--25 379 
PLATE XCVI. 

Page_ 

FIGURES 1, la. Solenastreajairbanksi var. columnaris Vaughan from Carrizo Creek, Cal.. __ ....... _._._. ___ ._._ 373 

L Side of specimen, natural size. 

la. Top of specimen, natural size. 

FIGURES 2, 2a, 2b, 2c. Solenastreafairbanksi var. normalis Vaughan, n. var., from Carrizo Creek, Cal. (See PI. 

XCVII, figs. 1, la) .. ____ ... __ ..... __ . ______________________________________________________ . _. ... . . . . . . . 373 

2. Corallites as revealed by a fracture parallel to their longitudinal axes, natural size. 

2a, 2b. Two areas to show calicular characters, each X 4. 

2c. Corallites as exposed by a fracture, X 4. 

380 
U. S. GEOLOGICAL SURVEY 

,)<.4 

REEF CORALS. 

PROFESSIONAL PAPER 98 PLATE XCVI 

2 
U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 98 PLATE XCVII 

1 XYz 

2 ~ 

X4 X4 

REEF CORALS. 
PLATE XCVII. 

Page. 

FIGURES 1, la. Solenastrea jairbanksi var. normalis Vaughan, n. var., from Carrizo Creek, Cal. (See Pl. XCVI, 

figs. 2, 2a, 2b, 2c)..................... . .... ... ........... . ............................................ 373 

1. Corallum, one-half natural size. 

la. Calices, X 4. 

FIGURES 2, 2a, 2b, 2c. Solenastreajairbanksi var. minor Vaughan, n. var., from Carrizo Creek, Cal............. 373 

2. Corallum, one-half natural size. 

2a, 2b, 2c. Calices, each X 4, from three areas. 

381 
PLATE XCVIIL 

Page. 

Solenastrea hyades (Dana) from the Pliocene Caloosahatchee marl of Florida.................................. 374 

FIGURES 1, la. Two views of the same specimen. 

1. Corallum, natural size. 

la. Calices, X 4. 

FIGURES 2, 2a. Two views of another specimen. 

2. Corallum, natural size. 

2a. Calices, X 4. 

FIGURE 3. Corallum of a third specimen, natural size. 

382 
U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 98 PLATE XCVIII 

REEF CORALS. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 98 PLATE XCIX 

1 la X4 

REEF CORALS. 
PLATE XCIX. 

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Solenastrea bournoni Milne Edwards and Haime, a recent species from the West Indies........................ 374 

FIGURES 1, la, lb, 2. Cotypes of Solenastrea bournoni in the Museum d'histoire naturelle, Paris. 

1. Corallum, natural size; la, calic"s, X 4; lb, longitudinal section, X 4, of the same specimen. 

2. Calices of a second specimen, X 4. (This specimen may be the true type.) 

FIGUREs 3, 3a. Specimen labeled Cyphastrea oblita Ducha£saing and Michelotti, in the Museum d'histoire naturelle, Paris. 

3. Corallum, natural size. 

3a. Calices, X 4. 

The photographic negatives on which the figures in this plate a.re based were kindly supplied by Dr. Charles 

Gravier, of the Museum d'histoire naturelle, Paris. 

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Solenastrea bournoni Milne Edwards and Haime .... ___ . _________ . _ ... _ .................................... . 

FIGURE 1. Calices of a specimen from the Pliocene Caloosahatchee marl of Florida, X 4. 

FIGURES 2, 2a. Two views of the same specimen, from the Caloosahatchee marl. 

2. Transverse section of corallites, X 4. 

2a. Longitudinal section of corallites, X 4. 

FIGURES 3, 3a, 3b. Three views of a part of Duncan's type of Plesiastrea globosa (presented to the U. S. 

National Museum by the Geological Society of London), from "silt of the plain, Santo Domingo." 

3. Corallum, natural size. 

3a. Calices, X 4. 

3b. Longitudinal sectiol'l, X 4. 

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FIGURES 1, la. Mr£andra bowersi Vaughan, n. sp., from Carrizo Creek, Cal................................... 374 

1. Corallum, natural size. 

la. Part of calicular surface, X 2. 

FIGURE 2. Mr£andra labyrinthiformis (Linmeus), the type species of the genus, from Cocoanut Point, east side of 

Andros Island, Bahamas. View of calicular surface, X 2................................................ 374 

FIGURES 3, 3a, 4. Siderastrea mendenhalli Vaughan, n. sp., from Carrizo Creek, Cal............ . ............... 374 

3, 3a. Two views of the same specimen. 3, Corallum, natural size; 3a, calices, X 6. 

4. Calicular surface of another specimen, natural size. 

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FIGURE 1. Siderastrea mendmhalli var. minor Vaughan, n. var., from Carrizo Creek, Cal. Calices, X 4......... 375 

}i'IouRES 2, 2a, 3, 4. Siderastrea californica Vaughan, n. sp., from Carrizo Creek, . Cal ............. , . . . . . . . . . . • • 375 

2, 2a, Two views of \he holotype. 2, Upper surface of the corallum, natural size; 2a, calices, X 6'. 

3. Calices of a paratype, X 6. 

4. Calices of a second paratype, X 6. 

FIGURES 5, 5a, 5b, 6, 6a. Porites carrizensis Vaughan, n. sp., from Carrizo Creek, Cal. . . . . . • . . . . . . • . . . . . . . . . . . 375 

5, 5a, 5b, Views of the holotype. 5, Corallum, natural size; 5a, a calice retouched on a photograph, X 8; 

5b, the calice represented by 5a from the same photograph but without retouching. 

6, 6a, Calices of a paratype. In figure 6 one calice has been retouched on the photograph; figure 6a is from 

a photograph on which none of the calices were retouched. 

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