DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 325 



The type sj)ecies, D. trichiurus, Alcock, is represented by a specimen 7 inches long, 

 with the end of the tail missiug, obtained by the Investigator at station 104, at a depth of 

 1,(H)0 fathoms. 



Another species, D. melanocephalus, was obtained from station 111, 1,044 fathoms, 

 and station 117, 1,748 fathoms, mature females about 8 inches long. [Alcock, Ann. and 

 Mag. Nat. Hist., IS'Jl (July), 32.J 



NEOBYTHITES Goode and Bean. 



Tetranemaiopus, Gunther, MS. 



NeohyihUes, Goode and Beax, Troc. U. S. Nat. Mns., viii, 1885, 600. — Guntiier, Challenger Report, xxii, 

 1887, 100. — Vaillant, Exp. Sci. Travailleiir et Talisman, 282, (discussion under Bylhiles craxaus). 



Brotulids having the body elongate, compressed, covered with small scales, and the 

 head also scaled. Lateral line incomplete, obsolete posteriorly. Eye moderate. Snout 

 moderate, rounded, slightly produced, the lower jaw slightly included. No barbel. Teeth 

 villiform, in narrow bands in jaws and palatines. Vomerine teeth in V-shaped patch. 

 Two weak spines at angle of preoperculum, and a stronger one at the angle of the opercu- 

 lum. Gill-openings wide, the membranes deeply cleft and not attached to the isthmus. 

 Vertical fins united. Ventrals reduced each to a bifid ray. Branchiostegals, 8. Pseudo- 

 branchiai present, but small. Air-bladder present. Type, Weohythites Gillii. 



NEOHYTHITES GILLII, Goode and Bean. (Figure 289.) 



Neohythites Gillii, Goode and Hkan, Proc. IT. S. Nat. Mus., \iii, 1885, 601. — Gvnther, Cballtnger Report, 



XXII, 1887, 103. 

 Neobyihites ocellaliis, Gunther, loc. cil. and PI. xxi, Fig. B. 



Body compressed, its height (17 millimeters) contained 4g times in total length, and 

 less than length of head. Interorbital area convex, its width (5 millimeters) equal to diam- 

 eter of circular eye, 3§ in length of head and li in length of snout in young. 



Head comiiressed, deeper than broad, with wide sinuses, its length (18 millimeters) 

 contained 4J times in that of body; snout obtusely rounded, slightly produced. Mouth 

 large, the maxillary extending considerably behind the vertical through ])osterior margin 

 of eye, expanded posteriorly; the mandible still longer, its length (11 millimeters) about 

 2J times in the height of the body. Interorbital space convex. Teeth in villiform bands 

 in the jaws and on the palatines. Vomerine patch subcircular, with angles extended 

 posteriorly. 



Gill-rakers moderately long and slender, somewhat numerous, the longest about two- 

 thirds the diameter of the eye; eleven developed and three rudiments below the angle. 

 Pseudobranchiie absent. Gill-opening wide, the membrane deeply cleft, free from the 

 isthmus behind. 



A single long, flat spine attached to the posterior portion of the operculum, high up, 

 extending back along to its edge; a small hidden spine at lower angle of preoperculum. 



Nostrils small, the anterior one in a very short tube, almost upon the tip of the snout; 

 posterior nostril slightly larger, not tubular, immediately in front of middle of eye. 



Scales moderate, uiion head and on body, in 88 vertical rows, 7 rows between dorsal 

 origin and lateral line, which becomes obsolete in its posterior half; 10 or 17 from vent 

 forward to lateral line. 



Dorsal origin behind that of ventral and pectoral. Its distance from snout (21 milli- 

 meters) contained 4 times in total length. Its rays moderately long. Anal origin under 

 the eighteentli dorsal ray; its distance from snout (.'54 millimeters) contained 2^ times in 

 body length. Kays rather slenderer than those in the dorsal. The caudal rays are 6 or 7 

 in nund)er, their length (0 millimeters) contained 9 times in total lengtli. They are not 

 differentiated from those of the adjat'cnt fins. Pectoral origin well Ibrward, its base .some- 

 what concealed by the flap of the operculum ; its length (13 millimeters) about equal to 

 two thirds that of head. Ventrals each a bifid ray, the inner filament the longer, inserted 

 slightly in advance of the base of the i)ectoral and not far from humeral symphysis, and 



