Fig. 1, on Plate, represents one of the examples referred to, the principal portion of the figure showing a natural cast of the dorsal valve, with the umbonal portion of the ventral valve. In this figure the full length of the shell from back to front is not shown, but it is represented in the accompanying diagram, Fig. 2.

WASHINGTON, D. C., December 3, 1879.

NOTE ON ACROTHELE.

By C. A. WHITE.

Among the fossils collected from Primordial strata at Antelope Spring, Southern Utah, by Mr. G. K. Gilbert and Mr. E. E. Howell, who were then connected with the explorations and surveys west of the 100th meridian, were a number of examples of a discinoid brachiopod. This form I described and figurea* under the name of Acrotreta? subsidua, referring it to that genus provisionally. None of the examples were in a condition to show all the generic characters clearly, but certain features in these shells indicated their possession of important differences from any genus then established and led me to suggest that they probably represented a new generic type. In the same year, 1876, Prof. G. Linnarsson, of Stockholm, Sweden, published a new generic form from the Primordial rocks of Sweden, under the name of Acrothele, which plainly includes Acrotreta? subsidua White. Professor Linnarsson des cribed two Swedish specics under this generic name (A. coriacea and A. granulata), and in 1879 he published a third species under the name of A. intermedia,‡ but A. subsidua is at present the only known American species. It is not unlikely, however, that some of the American species heretofore referred to Discina will be found to belong to Acrothele. WASHINGTON, D. C., February 1, 1880.

DESCRIPTION OF A NEW

Pinna stevensoni.

CRETACEOUS PINNA FROM NEW

MEXICO.

By C. A. WHITE.

Shell large, elongate-triangular in marginal outline; valves moderately convex; the convexity being slight and nearly uniform posteriorly, but much greater toward the front, where it amounts to an obtuse median angularity upon each valve, and where a transverse section of the shell has an approximately regular rhombic outline; upper border Expl. and Sur. West of the 100th Merid., Vol. IV, p. 34, pl. I, fig. 3, a, b, c, and d. † Bihang till k. Svenska Vet. Akad Handlingar, Band 3, No. 12, p. 20, pl. IV, figs. 44-52.

‡ Sveriges Geologiska Undersökning; Ser. C. Afhand. och Upps. No. 35, p. 25, pl. iii, figs. 40-44.

straight or nearly so; lower border slightly convex and longer than the upper border; posterior border nearly straight or slightly convex, truncating the shell obliquely downward and backward, meeting the upper border at a more or less distinct obtuse angle and the lower border by an abrupt curve. Surface marked by abundant coarse lines and imbrications of growth, which traverse the shell in slightly curved lines corresponding with the posterior border, and is apparently without trace of any radiating lines or ribs.

Entire length from beak to postero-basal extremity about 215 millimeters; breadth, from the postero-dorsal extremity to the base, measured at right angles with the upper border, 95 millimeters.

This shell is so unlike any described American species that no detailed comparison with any of them is necessary; but it is so closely related to P. legeriensis d'Orbigny, from the department of Sarthe, France, that it is not without some hesitation that I have decided to propose separate specific name. I have never had an opportunity to examine any of the few examples of P. legeriensis that have been discovered, and my comparisons are therefore only with the description and figures of d'Orbigny, in Pal. Française, Vol. III, p. 257, pl. 334. From these it appears that our shell differs from P. legeriensis in the following particulars. The angle of divergence of the upper and lower margins is not so great, in consequence of which the breadth of the shell is not proportionally so great; the curve by which the posterior border meets the lower border is more abrupt, and the greatest transverse diameter of the shell is near the median line instead of being much below it, as it is represented to be in P. legeriensis. The internal median grooves upon each valve, and also the undulations of the lower border, mentioned by d'Orbigny, appear to be entirely wanting in our shell.

Position and locality.-Cretaceous strata; about 1 miles southwestward from Fort Wingate, Northern New Mexico, where it was collected by Mr. James Stevenson, in whose honor the specific name is given. WASHINGTON, D. C., February 15, 1880.

NOTE ON THE OCCURRENCE OF STRICKLANDINIA SALTERI AND S. DAVIDSONI IN GEORGIA.

By C. A. WHITE.

A few months ago Lieut. A. W. Vogdes, United States Army, gave me a few fragmentary fossils from a collection which he had then lately made at Taylor's Ridge, in the town of Ringgold, Catoosa County, Georgia. The other fossils of this collection and the geology of the region referred to were discussed by Lieutenant Vogdes in the December, 1879, number of the American Journal of Science and Arts, pp. 475-477. He there refers, and doubtless correctly, the horizon from which he obtained the fossils he gave me to that of the Clinton Group

of New York. They are in the condition of natural casts in fine-grained sandstone, but I have quite satisfactorily identified a dorsal valve of Stricklandinia salteri and one of S. davidsoni Billings. If these two species are correctly identified, as they appear to be, their discovery in Georgia is especially interesting, because they have hitherto been found only in strata of the island of Anticosti; and also of the indication which they and their associates in the two regions named afford as to the equivalency of the Georgia, Clinton, Anticosti strata in America; and Upper Llandovery strata of Great Britain.

WASHINGTON, D. C., February 15, 1880.

DESCRIPTION OF A NEW FLOUNDER (PLEURONICHTHYS VERTICALIS), FROM THE COAST OF CALIFORNIA, WITH NOTES ON OTHER SPECIES.

By DAVID S. JORDAN and CHARLES H. GILBERT. Pleuronichthys verticalis sp. nov.

Form broad ovate, the outlines regular; head small, somewhat constricted behind the upper eye; eyes large, but smaller than in P. quadrituberculatus. Interorbital ridge narrow; a small tubercle or prominence in front of the upper eye; a large one in front of upper edge of lower; another larger and sharper at interior edge of the interocular space; another at the posterior edge of the interocular spine ridge. This latter is developed into a long, sharp, triangular spine, which is nearly as long as the pupil, and is directed backwards. A prominent tubercle at the posterior lower angle of the upper eye. Upper edge of opercle somewhat uneven, but no other tubercles present.

Mouth small, as in other species; the lips thick, with lengthwise plica.

Teeth in a broad band on the left (blind) side of each jaw; no teeth on the right side in either jaw. Gill-rakers very small, weak, and flexible, about ten in number. Scales essentially as in the other species, small, cycloid, imbedded, and scarcely imbricated. Lateral line nearly straight, with an accessory branch which extends to the middle of the dorsal fin.

Dorsal fin beginning on the blind side at the level of the premaxillary, there being but about four of its rays on the left side of the median line. Vertical fins less elevated than in the other species, the longest rays of the dorsal about half the length of the head. Anal fin preceded by a spine. Caudal peduncle short and deep. Caudal fin elongate, rounded behind. Pectoral short, nearly equal. Ventrals moderate, reaching anal spine.

Fin rays: D. 65; A. 45.

Color dark olive-brown, with round grayish spots, the body and fins mottled with blackish.

Proc. Nat. Mus. 80- 4

May 6, 1880.

The type, No.

United States National Museum, was taken in a trawl-net outside of the Golden Gate, and was procured by us in the San Francisco market.

There are apparently three species of the genus Pleuronichthys, as restricted by Gill, in the waters of California.

One of these is the common species in the San Francisco markets at present, being taken in some abundance in the trawl-nets off Point Reyes and the Farallones. This species is the Pleuronichthys cœnosus of Lockington's Memoir (Proc. U. S. Nat. Mus. 1879, 97), and, as Lockington suggests, it is probably identical with the Pleuronectes quadrituberculatus of Pallas. For this form we accept provisionally

the name quadrituberculatus.

A second species occurs farther south, two specimens having been procured by us at Santa Catilina Island, and one at San Luis Obispo. This form answers better than the preceding to Girard's description of his Pleuronichthys cœnosus, and it may for the present be identified with it. The specimen noticed by Lockington as "No. 4," "with the dorsal not continued downward nearly so far as the others," perhaps belongs to this species.

The third species is P. verticalis, described above.

The species may be readily separated, so far as we have observed, by the following characters:

* Dorsal fin beginning on the level of the lower lip, about ten of its anterior rays being on the left side; ocular region with four or more blunt prominences or tubercles, arranged as follows: one in front of upper eye, another at each end of the interorbital ridge, the posterior largest, but not spine-like, one behind the latter, and one or two more behind the upper eye; upper part of opercle uneven; lower jaws with a band of teeth on the right side similar to that on the left side, but narrower; fins high, D. 72, A. 46..........QUADRITUBERCULATUS. ** Dorsal fins beginning on the level of the upper lip, only four or five of its rays being on the left side of the median line.

+ Posterior prominence of interocular ridge developed as a strong backwarddirected spine; tubercular prominences present about the upper eye; no teeth on right side of lower jaw; fins rather low, D. 65, A. 45................ VERTICALIS. #Posterior prominence of interocular ridge scarcely elevated; other ocular tubercles obsolete; teeth; fins high, D. 68, A. 48 CONOSUS.