FISHES OF HAWAIIAN ISLANDS. 
665 
Hym.enoceph.alus striatulus, new species. Fig. 259. 
Type, 144 mm. long, from station 4122, off the southwest coast of Oahu, depth 192 to 352 fathoms; 
type, No. 51611, U. S. Nat. Mus. 
Very closely related to H. antrxus, differing in the much more slender habit, the smaller eye, 
with the horizontal diameter much longer than the vertical, the more projecting snout, the more 
numerous ventral rays, and the more spinous scales. 
Depth of body equaling length of snout and eye; head 4.8 in total length. D. n, 9 (to ii, 11); V. 
15 (usually 14); P. 15 (15 to 18). 
Head and body very slender; anterior profile not strongly arched as in H. antreeus ; projecting 
point at tip of snout more prominent than in antreeus, extending well beyond mouth; skull papery 
with excessively large sensory canals inclosed by delicate membrane; mouth large, oblique; maxillary 
reaching vertical from hinder margin of orbit; mandibular barbel usually obsolete, to be made out 
in one specimen with the aid of a lens; teeth minute, in narrow bands in the jaws, the mandibular 
band about half width of premaxillary band; interorbital width equal to length of snout; eye ellip- 
tical, its vertical diameter contained 1.4 times in the horizontal diameter, which is 0.3 length of head; 
preopercular angle broadly rounded, with crenulated border, the posterior edge oblique; gill-mem- 
branes rather narrowly joined anteriorly, entirely free from isthmus; gill-slits wide, as in H. antrxus. 
Dorsal spine slender and smooth, scarcely longer than some of the succeeding rays; base of first 
dorsal contained 1.75 times in interspace between dorsals; first anal ray in a vertical a trifle behind 
last ray of first dorsal; ventrals inserted noticeably in advance of pectorals; pectorals long and slender, 
their tips extending to opposite fourth or fifth anal ray, their length a trifle more than half length of 
head; outer ventral ray filamentous, reaching to base of ninth anal ray; vent immediately in front of 
first anal ray, its distance from base of inner ventral ray equaling distance from the latter to mandibu- 
lar angle; a small obscure lens-like body on middle line of breast, as in H. antreeus; a similar body 
immediately before vent, the 2 joined by a raised strand along inner abdominal wall; scales very thin 
and caducous, an occasional patch only being present; 4 series between lateral line and base of first 
dorsal; those on breast, sides of body and tail essentially similar, and much rougher than in H. 
antrxus, each usually with from 20 to 30 spines, arranged in 4 to 6 parallel oblique series (quincunx 
order); scales along sides of shoulder-girdle and on under side of mandible smooth. 
In color, almost exactly like H. antrxus. The body was light olive in life, with narrow dark 
margins to the scales on the back; lower' half of caudal portion of body marked with coarse black 
pigment spots, many of which are arranged in oblique or horizontal rows; under a lens, the central 
area of many of these spots shines with metallic luster; somewhat finer specks, more closely crowded, 
form a wide dark band along middle of tail, which does not show the conspicuous narrow line char- 
