2494 Bulletin 4.7, United States National Museum. 



oblique, maxillary reaching vertical from middle of eye; jaws even at tip, 

 the mandible slightly included laterally; mandibular teeth in a moderate 

 band anteriorly, the inner series enlarged, narrowing posteriorly to a sin- 

 gle row ; prernaxillary teeth of uniform size, in a narrow band through- 

 out; vomer with 4 canine-like teeth; palatine teeth small, in a single 

 close-set series. Distance from origin of dorsal to occiput slightly less 

 than that from occiput to posterior nostril; head and trunk contained 3| 

 in tail. Body brownish in spirits, fins whitish, translucent ; everywhere 

 dusted with black specks ; tail and fins distinctly blackish posteriorly ; 

 orbit blackish above; gill cavity silvery, blackish anteriorly; mouth 

 blackish, except anteriorly; peritoneum black, the color not showing 

 through the abdominal wall. Similar to L. Jierasfer, differing in the much 

 smaller head, longer, slenderer body, the thicker skin with more evident 

 mucous pores, and in the more restricted gill openings. Aleutian Islands, 

 in moderately deep water. Only the type known, a specimen about 5 

 inches long. (Gilbert.) (parvus, small; -ceps, head.) 



\Lycodapus parviceps, GILBERT, Kept. TJ. S. Fish Comm. 1893 (1896), 455, north of Unalaska 

 Island at Albatross Station 3324, in 109 fathoms. (Coll. Dr. Gilbert.) 



2866. LYCODAPUS EXTENSU8 (Gilbert). 



Head 6f; depth 15; eye 4 in head; snout 3f; iuterorbital width 1 in 

 eye; pectoral 2f in head. D. 96 (the extreme end of the tail wanting). 

 Gill openings as in L. Jierasfer, extending well above base of ventrais. 

 Skin thin, the mucous pores inconspicuous, evident on mandible and 

 along margin of preopercle. Upper profile of head longitudinally con- 

 cave, shaped as in L. Jierasfer, but slenderer, its depth greater than that 

 of body. Mouth oblique, the maxillary reaching vertical from middle 

 of eye, 2 in head. Teeth in narrow bands in each jaw, tapering 

 laterally to single series; vomerine teeth more numerous than in L. 

 parviceps or L. Jierasfer, small, not canine-like, in a single series; pala- 

 tine teeth wanting, as in some individuals of L. Jierasfer. Occiput mid- 

 way between front of dorsal and anterior nostril; pectorals slenderer 

 and longer than in L. Jierasfer. Head and trunk contained 23 times in tail. 

 Color light brownish, the black peritoneum visible through the skin of 

 the abdomen; mouth and gill cavity largely dusky; a narrow dark-brown 

 streak along base of dorsal and anal, occupying, toward tip of tail, the 

 entire height of both fins. An extremely slender elongate form, with 

 head smaller than L. Jierasfer, but otherwise resembling that species more 

 t^han L. parviceps. Aleutian Islands, in rather deep water. Only the type, 

 a specimen 4 inches long, known. (Gilbert.) (extensus, stretched out.) 



Lycodalepis extensus, GILBERT, Kept. TJ. S. Fish Comm. 1893 (1896), 455, north of Unalaska, 

 at Albatross Station 3324, in 109 fathoms. (Coll. Dr. Gilbert.) 



Family CCX. FIERASFERID^E. 

 (THE PEARL-FISHES.) 



Body elongate, compressed, tapering into a long and slender tail; no 

 scales; teeth cardiforin, on jaws, vomer, and palatines; canine teeth often 

 present; no barbels; lower jaw included; vent at the throat; gill mem- 



