DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 



Measiiremeiils. 



141 



Total length 



Snout to hrauchial slit. 



Snout to dorsal 



Snout to anus 



Height of trunk: 



At pectoral 



At belly 



At anus 



Width of mouth 



Diameter of eyeball . . . 

 Length of pectoral 



Numbers. 



Teeth 



Branchioategals 



Pectoral rays 



Family ILYOPHID^E, Gilbert. 

 Uyophidida;, Gilbert, in Jorhan aiul Davi.s, Rtpt. V. S. F. C, 18S8 (1891), (i70. 



Apodal fisbe.s, with a conical and slender snout, luodeiate.ly strong jaws, with sharp 

 teeth in bands ; teeth in a baud upon the vomer. Gape lateral. Gill openings se]>arate, 

 horizontal, inferior. Branchiostegal rays long, curved, as in Simenchelyidw. Lips obso- 

 lete. Tongue obsolesceut. Scales present, minute. General aspect similar to that of 

 Synaphohranchidw. 



The family is at present composed of a single genus. 



ILYOPHIS, Gilbert. 

 Hvpphis, Gilbert, hic. cit. 



Body scaly; pectorals well developed; lateral line prominent; gill slits horizontal, 

 inferior, well separated; nostrils lateral, the posterior immediately in front of the eye; 

 the anterior with a short tube, near tip of snout. INIa.xillaries as in tSynaphohrancJitis ; the 

 clamping processes closely appressed to the side of the vomer behind its head; lower jaw 

 strong, apparently with the coronoid process well developed; series of teeth on head and 

 shaft of vomer continuous; no li])s; tongue little developed, with narrow free margin; 

 branchiostegal rays 15 in number (as determined without dissection), not shortened, .some 

 of them curved around and above the opercle. Dorsal, anal, and caudal confluent, rather 

 high, the rays clearly visible through the skin; dorsal beginning well forward, its origin 

 immediately behind the base of pectorals; origin of anal near end of anterior third of body. 

 (Gilbert.) 



It is represented by a single siiecies, Ilyo2)hi.s hriinneu.i, Gilbert (fig. !<•-), obtained by 

 the Albatross off the Galapagos*. 



* Ilyopkis brunneus, Gilbert, loc. cit. 



Body narrow, compressed tlirongliout; snout and jaws slender; gape one-half leugfli of head, extend- 

 ing beyond the eye for a distance less than the diameter of the latter; maxillary teeth small, bluntly conir, 

 in narrow band ; teeth on vomer large, couic, those on shaft of vomer in single row; teeth in mamlible iu 

 narrow baud, those ou the inner series enlarged and retrorse though less than half the size of the vomerine 

 teeth ; front of pujiil over end of second third of length of jaw ; gill slits narrow, inferior, luirizouf al, cres- 

 cent-shaped, about equaling horizontal diameter of eye, their lower (anterior) ends separated by a distance 

 equal to their own length, their upper (posterior) ends by li times that distance; head 2 iu trunk; he.ad 

 and trunk 3^ in total length; pectorals small, 6 in head, rays evident; scales very line, arranged iu groups 

 at right angles to one auother; lateral line running high anteriorly, its pores white and conspicuous. Color 

 brown, the tins, lower side of head, and branchial regions darker. {Gilbert.) 



