DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 



Measurements. 



Ml 



Total length 



Snout to branchial slit . 



Snout to dorsal 



Siiiiut to anus 



Heighl of trunk: 



At pectoral 



At belly 



At amis 



Width of mouth 



Diameter of eyeball 

 Length of pectoral — 



Numbers, 



Teeth 



Branchiostegals 



Pectoral ravs 



Family ILYOPHID^, Gilbert. 

 Ilyophididce, Gilbert, in Jordan and Davis, Kept. U. S. P. C, 1888 (1891), 670. 



Apodal fishes, with a conical and slender snout, moderately strong jaws, with sharp 

 teeth in bands ; teeth in a band upon the vomer. Gape lateral. Grill openings separate, 

 horizontal, inferior. Branchiostegal rays long, curved, as in SimenchelyidcB. lips obso- 

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

 Synaphobranchidce. 



The family is at present composed of a single genus. 



ILYOPHIS, Gilbert. 

 Ilyophis, Gilbert, loo. 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. Maxillaries as in Synaphobrcmchus ; the 

 clamping processes closely appresscd 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 lips ; 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 Dear end of anterior third of body. 

 (Gilbert.) 



It is represented by a single species, Ilyophis brunneus, Gilbert (fig. 162), obtained by 

 the Albatross off the Galapagos*. 



" Ilyophis hnunii its, Gilbert, loe. cit. 



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

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

 in narrow band ; teeth on vomer large, conic, those on shaft of vomer in single row; teeth in mandible in 

 narrow band, those mi the inner Beries enlarged and retrorse though lrss than halt tin- sizr of the vomerine 

 teeth; front of pupil over mid of second third of length of jaw; gill slits narrow, inferior, horizontal, cres- 

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

 equal to their own length, their npper (posterior) ends bj 11 times thai distance; head 2 in trunk; head 

 and trunk 3J in total length; pectorals small, 6 in head, rays evident; scales very tine, arranged in groups 

 at right angles to one another; lateral line running high anteriorly, it > pores white and conspicuous. Color 

 brown, the fins, lower side of head, and branchial regions darker. (Gilbert.) 



