DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 



159 



No trtu-es of a lateral Hue. Vent premediau. Rays of vertical fius slender and flexible. 

 Tail free, teriuiuatiug iu slender point. 



EURYPHAKYNX PELECANOIDES, Vaillant. (Figure 176.) 



Eurypharijnx peiccanoides, Vaillant, Comptea Rendus Acad. Sc, Paris, xcv, 1226, Dec. 11, 1882; Exp. Sci. 



Tr;iv:iilleur ct Talisman, 198, jil. xvii. — Gill and Ryder, Joe eit. 

 Siccopharynx pelecanoides, Gunthkh, Challenger Report, xxii, 1887, 262. 



Both jaws possess merely feeble dental granulations, but the lower jaw is armed in front 

 with a pair of slender curved teeth (2 millimeters long). The length of the jaws is about 

 one half of that of the body. The origin of the dorsal fin is nearer to the end of the snout 

 than to the vent; neither the dorsal nor the anal fin reach the end of the tail (which termi- 

 nates in a small, skinny lobe). Gill-opening a very small round opening. No bluish-white 

 line along the back. (Gunther.) 



" This animal," writes Gill, "is about 0.47 meter long and 0.02 meter high at the most 

 elevated part and is of an intense deep-black color. The body, the form of which is masked 

 in front by the abnormal mouth, which will be mentioned further on, resembles that of 

 Macrurm; it becomes regularly attenuated from about tlie anterior fourth, the point at 

 which the external branchial orifice is seen, and terminates in a point at the caudal extrem- 

 ity ; the anus is situated at the junction of the anterior third with the posterior two-thirds 

 of the body. 



"What gives this fish a very peculiar physiognomy is the arrangement of the jaws and 

 the structui'e of the mouth, which are even an exaggeration of what Mr. Ayres has described 

 in Malacostem niger. Although the head is short (scarcely 0.03 meter), the jaws and the 

 suspeiisorium are excessively elongated; the latter did not measure less than 0.095 meter; 

 and from this it results that the articular angle is carried very far back, to a distance from 

 the end of the muzzle equal to about 3J times the length of the cephalic portion." 



GASTROSTOMUS, Gill and Ryder. 

 Gastroatomua, Gill and Ryder, Proe. U. S. Nat. Miis., 1883, vi, 271-273. 



Eurypharyngids with the cranium abbreviated and little or no longer than broad, 

 minute acute conic teeth depressed inward in a very narrow band on the jaws (no en- 

 larged teeth at the extremity of tlie mandible), and the tail with an eradiate membrane 

 under its terminal portion. Gill-opening close to angle of mouth. 



GASTROSTOMUS BAIRDII, Gill and Ryder. (Figures 181, 182.) 



Gastroatomus Bairdii, Gill and Ryder, Proc. U. S. Nat. Mus., 1883, vi, 271. 



The cranium forms about one-thirtieth or less of the extreme length, and is as broad as 

 long; the jaws are excessively elongated, being nearly (in large) or more (in young) than 

 7 times longer than the cranium; there are about 160 rays in the dorsal fin and about 

 107 in the anal; the pectorals are very small, being only about as long as the diameter of 

 the eye, and little more tlian twice as long as wide at the base, and have about nine simple 

 rays. The rays of the unpaired fins are quite flexible in the small individuals, but quite 

 rigid and more perfectly ossified in the larger; they become obsolete toward the end of the 

 tail. Tlie rays, which are rigid and well ossified anteriorly, become shorter, very slender, 

 and flexible — in fact, almost as limp as threads near the end of the tail. The vertebral 

 bodies become longer and more attenuated toward the end of the tail. 



Meter. 



Extreme length 47 



Body : 



Height at branchial region 035 



Height at anus 025 



Height at commencement of anal fin 02 



Length of alidominal cavity 05 



Met«r. 

 Cranium : 



Length 015 



Width 015 



Interorbital area Oil 



Orbit, diameter 003 



