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tinctly visible, beneath the cuticle, when dried, and the upper marginal plates are relatively larger than in the adult. The papulæ are few and scattered. In this stage, it agrees in all respects with the genus Marginaster Perrier and Lasiaster Sladen, both of which are probably the young of Porania or Poraniomorpha.
Four allied species of this genus are known from the Southern
Purania spinulosa Verrill, Proc. U. S. Nat. Mus., vol. 2, p. 202. 1877.
B. range, 80 to 640 fath. Rare below 400 fath. Most common in 150 to 250 fath. In one instance, off Cape Hatteras, taken in 48 fath. Off Cape Cod in 80 and 118 fath. Taken at 42 stations from 41° 80' 30'' to 35° 12' 30'', mostly in the warm area.
Var. rudis: A variety of this species has small divergent groups of longer and somewhat enlarged spinules on more or less of the actinal interradial plates, while the rest of the plates have the normal small spinules.
Var, inermis : This variety lacks the marginal spines on the infero-marginal plates, except near the ends of the rays.
There is considerable variation, also, in the number of spines on the jaw-plates.
A very large specimen, with the radii 80mm and 46mm, taken in 90 fathoms, off Martha's Vineyard, has thick, tumid margins, with the infero-marginal plates forced downward to the under side; many of these plates along the disk are destitute of marginal spines, or have them in a more or less aborted form; toward the tips of the rays the marginal spines become normal, but stouter than in smaller specimens.
This is closely allied to P. rosea Duben and Koren, of northern Europe. PORANIOMORPHA BOREALIS Verrill. Asterina borealis Verrill, this Journal, vol. xvi, p. 213, 1878; Verrill, Expl. made by the Albatross in 1883, in Ann. Report U. S. Fish Comm., vol. xi,
pl. 18, figs. 46, 464, 1885. Porania borealis Verrill, Check List, 1879; Ann. Report U.S. Com'r. of Fish
and Fisheries, for 1882, vol. x, p. 659, 1884.
B. range, 64 to 225 fath., rare. Belongs to the cold area. Taken at 4 stations, from 44° 26' to 39° 49' 30''. Also in the Gulf of Maine, in 110 fathoms, 1874. Fishing Banks, N. lat. 45° 25', W. long. 57° 10', in 170 fathoms.
The specimen from the Banks is much larger than any of the others. Radii 35mm and 23mm. The dorsal papular pores are very numerous and conspicuous over most of the dorsal surface, in large clusters. The ventral plates are nearly uniformly covered with slender needle-shaped spinules of nearly uniform size, no groups of larger spinules being present on them.
The spinules, above and below, as well as the adambulacral spines, are decidedly longer and more slender than in P. spinu. losa. The upper inarginal plates are conspicuous, swollen, elongated vertically, but have no special spines.
• A row of papulæ, between the upper and lower plates. RHEG ASTER ABYSSICOLA, sp. nov.
B. range, 2045 fathoms, N. lat. 37°, W. long. 71° 54'.
Greater radius, 35mm; lesser 14mm; elevation at center, 17mm. Form five-ra yed, stellate, with the disk flat beneath, tumid above, and indented by a distinct groove at the interradial angles. Rays tumid at base, with the distal part roundish, slender, and uniformly tapered. Abactinal plates rather large, concealed by the cuticle, and everywhere bearing small, blunt, well-separated, simple spinules, which are more or less covered by the integument. Papulæ small, scattered singly over most of the dorsal surface. The lower marginal plates are small, somewhat prominent, and bear an irregular group of six or eight small, sharp spinules, which forin a distinct border along the under edge of the disk and basal half of the rays, but disappear gradually before reaching the tips of the rays. Actinal plates entirely concealed by the integument; each one bears a divergent group of four to six or more small, sharp, rather stout spinules, which are unequal in size. Each adam. bulacral plate usually bears an obliquely transverse row of about five somewhat long, subacute spinules, of which the middle ones are a little longer than the others, and in some cases the row is double; the innermost is borne upon the inner angle of the plate, which projects somewhat into the furrow. The ambulacral feet are large, biserial, and furnished with well-developed terminal suckers. The inner end of each jaw bears four rather stout, sharp spines, similar to those of the adambulacral plates,
A single specimen (No. 8140) was taken at station 2226, off Delaware Bay.
Two allied species (R. Murrayi Si. and R. tumidus (Stuxb.) Sl. are found at moderate depths on the northern European coast; the last also occurs in the Arctic Ocean.
Family AsTERINIDÆ. ASTERINA PYGMÆA Verrill.
This Journal, vol. xvi, p. 372, 1878.
B. range, 52 to 92 fath., Gulf of Maine. Allied species are found in nearly all seas. TREMASTER MIRABILIS Verrill. Proe. U. S. Nat. Mus., vol. ii, p. 201, 1879; Expl. by the Albatross in 1883,
pl 18, fig. 51, 1885. B. range, 150 to 250 fath., rare. Known only from the Banks off Nova Scotia and Newfoundland, from N. lat. 47° 6' to near George's Bank. All the specimens have been received from the Gloucester fishermen. No other species of this remarkable genus is known.
(To be continued.]
Art. XIV.-Lower Cambrian Rocks in Eastern California ;
By CHAS. D. WALCOTT.
[Read before Geol. Soc. America, Baltimore meeting, Dec. 27, 1894.] The only Lower Cambrian rocks of California known to me occur in the White Mountain range of Inyo County, east of Owen's Valley, with the single exception of one small mass west of Big Pine, which is in the foothills of the Sierra Nevada. That portion of the White Mountain range lying near the Waucobi Canyon is commonly referred to as the “White Mountain range,” while the portion to the south is called the “Inyo range.” Prof. J. D. Whitney refers to the ranges (Inyo and White Mountain), stating that little is known of the geology except that, from Bend City for twenty-five miles north, their western base and slope seem to be made of slate and other stratified rocks generally dipping to the southwest and often much contorted. These slates are said to alter. nate with beds of limestone. In these rocks a single fossil was discovered, opposite Camp Independence, by Dr. Horn. This species was considered by Mr. Gabb as identical with a Triassic species which had been found in the Upper Trias of the Alps. From this Professor Whitney identified the strata along the western flanks of the Inyo and White Mountains with the rocks of Washoe, which were referred to the Trias.* .
On a map issued by the California State Mining Bureau in 1891,+ eight areas of limestone are indicated on the line of the White Mountain and Inyo ranges. Some of these are described in the report of the State Mineralogist for 1888.6 In his report * Geol. Surv. California; Geology, vol. i, 1865, p. 459.
Preliminary Mineralogical and Geological Map of the State of California, 1891.
† California State Mining Bureau ; Eighth Ann. Rep. State Mineralogist for 1888,
on Inyo County Mr. W. A. Goodyear, who was an assistant in the State Survey under Prof. J. D. Whitney, speaks of the Inyo and White Mountain ranges as a part of the great Paleozoic formation which occupies so extensive an area in the Great Basin. He also describes, * in the form of an itinerary, a geological exploration of parts of the range, noting the occurrence of various stratified rocks and granites.
During the summer of 1894, accompanied by Mr. F. B. Weeks, I crossed the range over the toll-road leading from Big Pine to Piper's ranch, in Fish Lake Valley, and penetrated into it from the western side in Waucobi, Black and Silver canyons.
The ascending section exposed in the ridge on the north side of Black Canyon is as follows:
1. Gray and yellowish, arenaceous limestone, occurring
in low hills above the Quaternary --2. Massive, bedded, compact, fine-grained, often saccha
roidal, light-gray, siliceous and arenaceous limestone (strike N. 10° W. mag., dip 20° E.). Al 100 feet from base of this division a dike of basalt 40 feet in thickness cuts through and displaces the limestone in the vicinity of the dike, so as to give it a dip of from 70° to 80° E. Above the dike the dip
of 20° is very quickly resumed. At 160 feet from the base a band of white limestone occurs, which contains numerous small concretions
of limestone. At 230 feet above the dike occurs a band of shaly limestone, which has buff-colored partings; and irregular, buff-colored, sandy laminations occur in
thin layers in the thick-bedded limestone. No. 2 may be subdivided as follows:
a. Light-gray and white limestone .......... 500 ft. b. Buff and gray, more arenaceous limestone,
with a band of cherty limestone 20–25 feet
thick at 125 feet from its base -------... 170 ft. c. Gray, arenaceous limestone, cherty at top., 115 ft. d. Shaly and thick-bedded, sandy limestone,
cross-bedded in places, with yellowish-buff
thick-bedded and shaly quartzite....... 145 ft. e. Massive, bedded, coarse, arenaceous, gray
limestone, passing into buff-colored and
* Loc. cit., p. 290.
h. Gray, arenaceous limestone, with bands of
buff-colored, mostly thick-bedded lime-
stone, with inclosed brecciated, thin-bedded
..... 5 ft. k. Dark, banded quartzite...... ------... 30 ft. 1. Massive, bedded, gray, arenaceous limestone 225 ft. Total of No. 2 ...
1,525 ft. 3. Dark, irregular, thin-bedded, siliceous slates, with
interbedded, dark, quartzitic sandstone (dip 25-30 E.
.... 635 ft. The section is terminated at this point by a fault line.
On the north side of Silver Canyon, No. 3 is well exposed, and is estimated to have a thickness of 2,000 feet. Above this a series of limestones and calcareous and siliceous shales occurs, and some interbedded, dark, quartzitic sandstones, that extend upward 1,000 feet. Near the base a massive, bedded limestone 100 feet in thickness occurs, in which great quanti. ties of Lower Cambrian corals (Archæocyathinae) occur. This series is capped by about 200 feet of compact, thin-bedded, arenaceous argillite, with interbedded layers of dark-brown, fine-grained quartzite.
The entire section, briefly summarized from summit downward, is as follows:
4. Upper arenaceous beds ------ .... 200 ft.
-- 2,000 ft.
.--. 1,700 ft.
Total .............................. 4,900 ft.
In round numbers the section exposed in the White Mountain range, between White Mountain peak and Waucobi Canyon, is 5,000 feet in thickness.
No fossils were found in the lower limestone. Numerous annelid trails occur in the lower siliceous series, and in the slaty portion near the summit heads of Olenellus were found. In places the lower portion of the upper limestone series is almost a solid bed of different forms of the Archæocyathinæ. Ethmophyllum whitneii Meek is very abundant, and the genera Protopharetra, Coscinocyathus, and probably Archæocyathus occur. Ethmophyllum ranges throughout the limestone series into the base of the shales in Tollgate Canyon, where it is associated with Cystidean plates and fragments of Olenellus. On the north side of Silver Canyon the Archæocyathinæ are