ures about 2 millimeters. The second arch has about the same number, while on the third there are but 6 or 7, very small, and present only in the angles, while in the fourth there are about the same number, very inconspicuous.

The dorsal fin originates above the middle of the operculum, and at a distance from the snout equal to twice the length of the snout.

The anal fin is composed of about 100 spines and rays. Owing to the mutilation of the specimen it is impossible to determine how many there are of each, but there are supposed to be about 28 rays normally united by a membrane into a fin.

The caudal is also imperfect, but the middle rays are seen to be about half as long as the remnants of the external rays. The fin is supposed to resemble in shape that of Lepidopus caudatus.

The pectoral originates under the tip of the opercular flap. Its outline is rounded above instead of emarginate, as in Lepidopus caudatus. Its longest ray equals in length the postorbital part of the head.

The ventrals originate at a distance from the snout equal to that of the base of the pectorals from the same point. They are rudimentary and represented by minute scutes, the length of which is 34 millimeters in the specimen before us, and about equal to half the interorbital width. Branchiostegals 7; D. 154; A. 100; P. 12; V. I.

Cæcal appendages 8 in the specimen examined. Some, however, may have been lost, the abdominal viscera having been partly digested by the halibut, in the stomach of which it was found.

Color: Uniform silvery, with traces of dark color upon head and tail.

Measurements.

Taken by Capt. Roderick Morrison (schooner Laura Nelson), from the stomach of a halibut.

Number of cæcal appendages ...

U. S. NATIONAL MUSEUM, Washington, D. C., Dec. 30, 1881.

9

8

17+

110

42

111

31

VII

154

100

12

I, I

8 (1)

DESCRIPTION OF A NEW SPECIES OF POMADASYS FROM MAZAT. LAN, WITH A KEY TO THE SPECIES KNOWN TO INHABIT THE PACIFIC COASTS OF TROPICAL AMERICA.

By DAVID S. JORDAN and CHARLES H. GILBERT.

Pomadasys cæsius sp. nov.

Allied to P. pacifici (Gthr.).

Head, 3 in length (3 with caudal); depth, 23 (2 with caudal). Length (28158), 94 inches; D. XII, 16; A. III, 9; scales, 6–52–13. Body ovate, compressed, the back rather strongly arched; anterior profile rather steep and straightish, gibbous between eyes and also behind them, slightly depressed above eyes and at the nape. Ventral outline considerably arched. Caudal peduncle moderate, about half as long as head, and somewhat longer than deep.

Head short and deep; deeper than long. Snout very short, blunt and thick, about one-third length of head. Mouth very small, the maxillary not quite reaching to the front of the eye, its length (from tip of snout) 3 in head. Teeth cardiform, in broad bands, the outer series enlarged, but smaller than in P. pacifici. Eye large, 34 in head, shorter than snout, about one-fourth wider than the broad preorbital. Lips thick. Chin with a median furrow and two pores; lower jaw included. Anterior nostril much larger than posterior. Preopercle rather weakly serrate, its upright limb somewhat concave. Gill-rakers short and weak, about 10 on lower limb of arch.

Scales rather large, arranged as in related species, those above the

lateral line forming series parallel with the back, but placed so that the cross rows are very oblique. Soft parts of vertical fins almost entirely covered with small scales; series of scales also on membrane of pectorals and ventrals. Scaly sheath of vertical fins well developed.

Dorsal fin low, rather deeply emarginate, its spines very strong, the second spine slightly longer than the eye, and two-thirds the height of the third, which is but little shorter than the fourth or longest, and about two-fifths length of head; soft rays more than two-thirds height of longest spines. Caudal rather large, moderately forked, the upper lobe somewhat the longest, about four-fifths length of head. Anal rather low, its distal margin perfectly straight, vertical; second anal spine very robust, half length of head, half longer than the third spine, which is much lower than the soft rays. Ventral fins 13 in head, about reaching vent. Pectoral fins long, subfalcate, a little longer than head, nearly or quite reaching anal.

Color in life, grayish-silvery above, with yellowish tinge; lower part of sides with indistinct darker streaks, formed by clusters of dark points on the margins of the scales. A faint dark bar, most distinct in the youngest specimens, extending from the region in front of the dorsal to, or a little below, the base of pectorals. In young specimens this bar is as wide as the eye, growing narrower below, but in the adult it is scarcely wider than the pupil. No trace of the black cross-bars seen in P. dorii and in P. pacifici, nor of the dark spots seen in P. furthii, nor of the lengthwise stripes of P. bilineatus and P. virginicus. Vertical fins and pectorals dusky yellowish; distal half of ventrals and base of anal blackish. Upper part of head dusky, especially between eyes. Lining of opercle pale, with yellow patches in life. Peritoneum white.

This species is known from three specimens (28158, 29632, and 28333), obtained in the harbor of Mazatlan. It was not seen at Panama.

The species of Pomadasys thus far known from the Pacific coast of tropical America may be readily distinguished by the characters given in the following table:

ANALYSIS OF SPECIES OF POMADASYS FOUND ON THE PACIFIC COASTS OF MEXICO AND CENTRAL AMERICA.

a. Anal fin short, its rays III, 7 to III, 10; dorsal fin deeply emarginate, its spines more or less robust.

b. Anal spines strong, the second longer and much stronger than third.

c. Soft dorsal and anal with series of scales extending on the rays; outer teeth in upper jaw enlarged.

d. Body ovate; back elevated; depth greater than length of head; outer teeth moderately enlarged, pointed; lips thick.

(ANISOTREMUS* Gill.)

e. Scales above lateral line in oblique series, not parallel with the lateral line. f. Scales rather small, 50 to 70 in a horizontal series.