101. ICOSTEID^E ICICHTHYS. 621 



(groups of spines). L. about 12 inches. Pacific coast of United States ; 

 three specimens known, from deep water. 



(LockiDgton, Proc. U. S. Nat. Mas. ii, 63, 1880.) 



333. ICSCHTHYS Jordan & Gilbert. 

 (Jordan & Gilbert, Proc. U. S. Nat. Mus. 1880, 305: type Idchthys lockingtonl J. & G.) 



Body elongate, not elevated, not compressed at the bases of the ver- 

 tical tins. Head moderate. Eyes lateral. Mouth terminal, little ob- 

 lique, with small, sharp teeth in one series, in the jaws only. Prtmax- 

 illaries not protractile. Gill-membranes separate, free from isthmus; 

 p;ill-rakers long. Pseudobranchia? present. Branchiostegals 7. Body 

 covered with small cycloid scales. Lateral line continuous, unarmed. 

 Bases of fins without spinules; dorsal and anal fins long and low, com- 

 posed of soft rays only; pectoral fins moderate, their bases fleshy, as 

 in Icosteus; ventral fins small, thoracic, I, 5. Pyloric cosca about 0, 

 large. Bones all very flexible, cartilaginous. Deep-sea fishes, ( 

 to yield or submit; izUoq, fish in allusion to the flexible skeleton.) 



97O. I. locEiiaagnJoESB Jor. & Gilb. 



Plain brown, paler below, somewhat punctulate. Body oblong, some- 

 what compressed, the caudal peduncle rather slender. Head moderate, 

 compressed, with vertical cheeks, rather broad and slightly con vex above, 

 the snout abruptly descending. Mouth moderate, little oblique, the slen- 

 der maxillary scarcely widened at the tip, extending to beyond front of 

 pupil; anterior edge of the preniaxillary on the level of lower rim of 

 eye; lips thin; premaxillary tapering backward, not forming the whole 

 margin of the upper jaw; maxillary behind slipping entirely under the 

 membranous edge of the preorbital; preorbital rather wide, with one or 

 two series of rather large, thin, cycloid scales (other scales on head, if 

 any, now lost on the typical example); lower jaw prominent, projecting 

 in front, included at the sides. Teeth in jaws only, minute, sharp, closely 

 and evenly set, larger and less numerous than in Icosteus cenigiriatlcus. 

 Eyes large, lateral, longer than snout, 4 in head. Cheeks rather wide; 

 preopercle with a prominent crest, behind which are some radiating mu- 

 cous cavities; the bone with a broad, prolonged, flexible, membranaceous 

 edge, covered with radiating stria?, each of which ends in a flexible point. 

 Opercle and subopercle rather large, extremely thin, and each crossed 

 by radiating stria?. Branchiostegals 7. Gill-rakers long, slender, sharp, 

 close-set, and moderately stiff, their length nearly three-fourths the diam- 

 eter of the eye. Scales very small, soft, and smooth, covering the body 



