large; caudal fin well developed; under side of tail flattened with a blunt medial ridge.

Under side covered with a fine shagreen, like the skin of a shark, the roughnesses being triangular and closely set, depressible backwards; the skin below much as in Rhinobatus, but the prickles higher and sharper, the skin much rougher than in the latter genus.

The branchial region, from the nostrils to the pelvic bones, is entirely smooth, except the lower lip, which has a band of close-set prickles. A small tract in the middle of the pelvic area is prickly, and most of the abdomen proper, back to a point in front of the vent; the anterior and outer three-fourths of the pectorals below and about half the ventrals anteriorly and exteriorly also rough, as is the whole snout below, in front of the nostrils; whole lower surface of the tail and the surface of the fins rough with shagreen.

Above, the entire surface is covered with close-set stellated prickles of different sizes, largest on the base of the pectorals, and smallest about the eyes and on the outer edges of the fins.

Besides these are several stout, bluntish, slightly recurved spines, with stellate bases, placed as follows: One at the upper anterior angle of the eye and two behind it, the posterior the larger; a large spine on the back at the shoulder-girdle, in front of which are two or three on the median line, and a series on the middle line of the back of 10 to 12; two more on the tail between the dorsal fins; two series on the shouldergirdle, the inner of two, the outer of two to four. No other large spines on the body. No claw-like spines are present on the pectorals in the male examples seen, all of which are, however, immature.

This species is very abundant in the Bay of San Diego, where about twenty examples of both sexes, all very similar in size, were obtained. This species of the Asiatic genus Platyrhina in the waters of the United States is a very interesting addition to our fauna.

Proc. Nat. Mus. 80-3

May 6, 1880.

RHINOBATIDE.

53. Rhinobatus productus Ayres.

Very common.

GALEORHINIDE.

54. Mustelus californicus Gill.

Abundant. This species appears to be identical with the Atlantic Mustelus canis, itself indistinguishable from Mustelus hinnulus Blåinville, of the Mediterranean.

55. Triacis semifasciatus Grd.

Not uncommon.

56. Galeocerdo sp?

The jaws of a large shark, with the teeth similar in both jaws, triangu lar, oblique, deeply notched on the outer margin, and all strongly ser rate, are preserved by Mr. Pitcher, of San Diego. The shark was taken near San Diego, but south of the Mexican line. The width of the mouth is about a foot. I suppose this to have been a species of Galeocerdo.

HETERODONTIDE.

57. Heterodontus francisci (Grd.) Jor. & Gilb.

Common.

DESCRIPTION OF A NEW FLOUNDER (XYSTREURYS LIOLEPIS),
FROM SANTA CATILINA ISLAND, CALIFORNIA.

By DAVID S. JORDAN and CHARLES H. GILBERT.
XYSTREURYS LIOLEPIS, gen. et sp. nov.

GENERIC CHARACTERS.-Subfamily Hippoglossina, allied to Hippoglossina, Hippoglossoides, and Paralichthys (Pseudorhombus). Eyes and color on the right side; mouth large, oblique, with the teeth developed on both sides, stout, unequal, bluntish, in a single series; gill-rakers few, short, thick, almost triangular; scales small, cycloid, membraneous, oblong in form; lateral line simple, arched over the pectorals; caudal fin double-truncate, the angles rounded; dorsal fin beginning over the eye; anal fin preceded by a feeble antrorse spine; ventrals lateral; body oblong, moderately deep, rather thin.

This genus differs from Hippoglossoides in the arched lateral line, and from Hippoglossina in the cycloid scales and in its dextral habit. From most of the related genera it is separated by the few stout short gillrakers.

SPECIFIC CHARACTERS.-Form broadly elliptical, the profile continuous with the curve of the back; ventral outline from chin to past the ventrals nearly straight, the rest of the outline corresponding to the dorsal outline. Head moderate, shortish; mouth very oblique, not so large as in Paralichthys maculosus; the premaxillaries on the level of the pupil when the mouth is closed, the maxillary reaching to the posterior border of the eye; maxillary broad; teeth in a straight row, wide apart, unequal, conical, and blunt at tip, their number about "Teeth in

14+ 15 13+12

the lower jaw irregularly alternating large and small. In the upper jaw similar, but smaller and less obviously alternating. The middle tooth on the blind side in the upper jaw the largest.

Eyes large, close together, the lower slightly anterior; nostrils of right side above and in front of lower eye; upper nostrils turned over on the blind side; posterior nostrils largest, with a conspicuous flap. Interorbital space a narrow, elevated ridge, covered with very small scales; a few scales on the posterior part of the maxillary, none on the mandible. Preopercle with its posterior margin free, little movable; cheeks and opercles densely covered with small, oblong, cycloid scales. Branchiostegals 7.

Gill-rakers short, blunt, triangular, scarcely one-fourth as long as the eye, their edges slightly dentate. There are about 7 of the large ones on the middle and lower part of the gill-arch, some rudiments above. (There are about 24 long and slender gill-rakers in Paralichthys maculosus.)

Lateral line without dorsal branch, with a broad curve above the pectorals. Scales quite small, oblong, cycloid, thin and membraneous; little imbricated except behind, and somewhat imbedded in the skin, with some smaller supernumerary scales, especially below; scales much smaller on the thoracic region than on the sides. Scales of right and left sides similar. A series of small scales extending up each ray of the vertical fins.

Lateral line with about 123 scales, pierced by tubes; number of rows of scales perhaps a little greater than the number of tubes.

Dorsal fin beginning just in advance of the middle of the pupil, its first ray slightly turned toward the blind side; some of the anterior rays furcate; most of the rays simple; the fin rather low in front, gradually becoming higher to a point near the middle of the body, thence regularly diminishing behind, the last ray being near to the base of the caudal; the caudal peduncle very short; anal fin similar, its highest ray opposite the highest of the dorsal; a weak antrorse spine at beginning of anal; ventrals shortish, reaching past front of anal; pectoral of right side. about as long as head, that of left side half as long. Caudal fin somewhat double-truncate, with rounded angles, the middle rays being produced.

Fin-rays: Dorsal, 82; anal, 64; ventrals, 7.

The typical example of this species was taken on a hook on the west side of the island of Santa Catilina, Los Angeles County, California.

DESCRIPTION OF A NEW RAY (PLATYRHINA TRISERIATA), FROM THE COAST OF CALIFORNIA.

BY DAVID S. JORDAN AND CHARLES H. GILBERT.

PLATYRHINA TRISERIATA.

Disk broad-ovate, broader than long; the snout very bluntly rounded, not projecting; the angle formed anteriorly by the pectorals very obtuse; anterior margins of the pectorals slightly convex; tail stout, in form intermediate between Raia and Rhinobatus, its width at base about equal to the length of the snout and a little more than the interorbital width; tail much longer than the disk, not much depressed, its sides vertical, its lower lateral edges with broad horizontal fold, a slight groove above on each side of the median series of spines.

Dorsal fins similar, higher than long, the anterior far behind the end of the claspers; the posterior free margin of both fins very convex, not forming an angle. Caudal fin large, well developed both above and below, its outline entire, elliptical. Ventral fins with their margins entire, the claspers well developed. Pectoral fins extending forward to a point but little short of the tip of the snout.

Rostral ridges wide apart at base, rapidly convergent, inclosing a triangular area; a slight translucent space separates this from the opaque pectorals; eyes small, wide apart, the broad spiracles close behind them.

Mouth broad, its width equal to the distance from its front margin to the tip of the snout; a deep crease passing around the mouth behind, in front of which the lower lip has three folds of skin. Upper lip not developed, a strong fold of skin passing from the angle of the mouth on either side to the inner angle of the nostrils, thence straight across, joining its fellow on the opposite side, these folds enclosing a depressed, subtriangular, shaped area, which is bounded behind by the curved outline of the upper jaw. In this depression are three transverse cross-folds of skin. Nostrils broader than the interval between them, with a free fold behind, which is prolonged forwards and inwards in the middle, the rest of the fold being turned backward. Anterior edge of nostrils with a broad flap, the outer edge of which is much prolonged, overlapping the posterior flap, the inner edge covering the inner angle of the nostril.

Both jaws strongly and somewhat regularly curved. Teeth numerous, rather sharp, about 8, about twelve in a cross-series. Gill openings very

narrow.

Skin everywhere covered with a rather fine shagreen, almost precisely as in Rhinobatus productus. The asperities are smaller below, and coarser on the outer anterior margin of the pectorals, where there are also two or three irregular rows of sharp, curved, backward-directed spines. Four strong spines on the tip of the snout, forming a rhombic figure; four or five strong, bluntish spines around each eye, above and in front, the one at the upper anterior angle the largest.

A series of 22 very strong spines along the median line of the back and tail, and two more on the tail between the dorsal fins. On each side of the tail above is a similar series of ten spines, the first opposite the end of the base of the ventrals, the last opposite the front of the first dorsal; a single strong spine on the outer edge of the shoulder-girdle and two between the spine and the dorsal series.

Color almost exactly as in Rhinobatus productus. Olive-brown above, whitish beneath, the vertical fins paler. Rostral area and edges of pectorals somewhat translucent. No sharp markings of any kind anywhere.