DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 



Measurements. 



141 



Total K-ngtli 



Snout to Itraut-'hial slit 



Suont to dorsal 



Snout to auus 



Height of trunk: 



At pectoral 



AtbeUy 



At anus 



Width of mouth 



Diameter of eyeball . . 

 Length of pectoral . . . 



Numbers 



Teeth 



Branchiostegala 



Pectoral ravs 



Family ILYOPHID^, Gilbert. 

 Ilyophididce, Gilbert, iu Jordan aud Davis, Kept. U. S. F. C, 1888 (1891), 670. 



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

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

 horizontal, inferior. Brauchiostegal rays long, curved, as in Simcnchelyida: Lips obso- 

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

 Synaphohranch ida: 



The family is at present composed of a single genus. 



ILYOPHIS, Gilbert. 

 HyophiH, Gilbert, loc. 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 SyiiaiihoJnunchus ; the 

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

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

 shaft of vomer contiintons; no lips; tongue little developed, with narrow free margin; 

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

 of them curved around iind nbovi^ tlie opercle. Dorsal, anal, and caudal confluent, rather 

 high, the rays clearly visibh>. through the skin; dorsal beginning well forward, its origin 

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

 {Uilhert.) 



It is represented by a single species, IlyopMs brtinneuti, Gilbert (flg. 11)2), obtained by 

 the Albatross oif the Galapagos*. 



* Ihjnphis bniviictis, Gilbert, loe. cit. 



Body narrow, < ompressed tlirouglKnit; snout and jaws slender; gape one-half leujjtU of head, extend- 

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

 in narrow hand ; teeth on vomer large, conic, those on shaft of vomer in single row; tei^th in mandible in 

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

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

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

 equal to their own length, tlieir up])er (posterior) ends by 1| times tliat distance; head 2 in trunk; head 

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

 at right angles to one another; lateral Vmc running high anteriorly, its poies white and conspicuous. Color 

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



