220 Mr. A. Alcock on the Bathyhial Fishes 



minute and the ventrals singularly large, and there is a con- 

 spicuous luminous organ immediately in front of the eye ; the 

 dorsal tin is nearer to the snout than to the base of the caudal 

 and entirely in front of the anal. But the single specimen 

 has been too much damaged to become the type of a new species 

 and the subject of a description. 



Family StomiatidsB. 

 Thaumastomias, gen. no v. 



Allied to MalacostenSj Ayres. 



Body elongate, compressed, scaleless, with the vent not far 

 distant from the caudal tin. Head compressed, with the 

 cranium small, the snout short, and the cleft of the mouth 

 exceedingly wide. A long elastic muscular band passing 

 from the hyoid bone to the inner aspect of the mandibular 

 symphysis. Teeth acute, unequal, in single series in pre- 

 maxillaj, maxillre, mandibles, and palatines ; none on tlie 

 tongue. Eye moderate. Gill-covers rudimentary. One 

 dorsal fin opposite to the anal, situated in the posterior fourth 

 of the body, near the caudal. No pectoral fins. Ventral 

 fins situated in the anterior half of the body. Gill-openings 

 very wide. No air-bladder. 



22. Thaumastomias atrox^ sp. n. (PI. VIII. fig. 7.) 



Head small, mouth extremely wide. Body elongate, low, 

 compressed, not diminishing much to the origin of the vertical 

 fins, but there rapidly and symmetrically narrowing to the 

 caudal peduncle, which is not quite one fifth the body-height 

 in depth. 



D. 23. A. 25. C. circ. 25. P. 0. V. 6. 



Length of the head one fifth, height of the body one tenth, 

 of the total without the caudal. 



Snout truncated, broad, M'ith a slightly concave vertical 

 profile, its length one third the diameter of the eye. Eye 

 large, circular, its diameter about one fourth the length of tlie 

 head ; interorbital space wider than the eye, convex. On 

 each side there is a small luminous organ, about the size and 

 shape of a caraway-seed, below and partly in front of the 

 eye, and another large salient slipper-shaped one, in length 

 more than one third the length of the head, lying parallel 

 with the upper jaw behind the eye. Moutli enormous, its 

 cleft as long- as the head; its floor is completely wanting 



