342 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



gill-laminae. Head covered with a system of wide muciferous channels and sinuses, the 

 dermal bones being - almost membranaceous, whilst the others are in a semicartilaginous 

 condition. Notochord persistent, but with a superficial indication of the vertebral segments 

 (as in some Leptocephaline forms). (Giinther.) 



This genus is known from two species — A. mollis, Goode and Bean, and the type, A. 

 gelatinosus, Giinther (Challenger Report, xxn, 1887, 120, pi. xxvi, Fig. A) from station 184, 

 between northeast Australia and New Guinea, at a depth of 1,400 fathoms. 



APHYONUS MOLLIS, Goode and Bean". (Figure 299.) 



Aphyonus mollis, Goode and Beajs*, Bull. Mus. Comp. Zool., xn, 103. 



The body is much compressed, its greatest height (14 millimeters), G in its total length. 

 Head thicker than body, its height (15 millimeters) slightly greater. Length of head 20 

 millimeters) about 4^ in total; width (11 millimeters) over half its length. Snout, 3 J in 

 length of head. Eye not externally visible. Diameter of orbit, as seen through the skin, 

 about one-fourth length of head. Maxilla extends to vertical through posterior margin of 

 orbit, the mandible somewhat farther back, its length (13 millimeters) nearly equal to height 

 of body. A few weak teeth ou vomer, palatines and mandible, and very rudimentary ones 

 in maxillary; not visible to the eye, but appreciable to the touch. Gill-lamina? on the fourth 

 and rudimentary gill-rakers, 8 rudiments and 4 developed below the angle. Dorsal origin 

 almost over posterior edge of operculum, its distance from the snout \ of total length; tin- 

 rays, more than 110 well developed, the longest 3 in head. Anal origin slightly nearer base 

 of caudal than to tip of snout, its rays shorter than those in the dorsal. Pectoral with a 

 fleshy base; its origin somewhat behind that of the dorsal, its length equal to width of head. 

 Ventral origin in advance of that of pectoral, close to humeral symphysis; the fin is a sin- 

 gle simple ray, whose length (11 millimeters) equals that of the pectoral: its tip does not 

 reach the vent by a space equal to height of head. 



Skin not loose. Texture of body rather firm, not transparent, whitish. 



The type is a specimen obtained at Blake station ccxxi, lat.L'4° 36' N., Ion. 84° 5' W., 

 at a depth of 955 fathoms. 



This species is closely allied to Aphy<mv& gelatinosus, Gthr. 



RHODICHTHYS, Collett. 

 Rhodichthys, COLLETT, NorskeNordhavs Expect., Fiske, 1880, 153. — GCntiiei:, Challenger Report, xxn, 1887, 121. 



Head thick, body and tail strongly compressed, the latter tapering behind, enveloped in a 

 thin, transparent, scaleless skin. Vent immediately behind the humeral symphysis. Snout 

 swollen, overlapping the wide mouth. A few series of weak teeth in the jaws, none on the 

 vomer or palate. Eye of moderate size. Ventrals reduced to two filaments, each bifid, and 

 inserted on the hyoid. Vertical fins continuous, but with caudal rays differentiated. Gill- 

 openiugs very wide. Pyloric appendages 10. [Giinther after Collett.) 



RHODICHTHYS REGLNA. COLLETT. (Figure 303.) 

 Rhodichthys regina, Collett, Forh. Selsk., 1878, 99; Norske Nordhavs Exped., Fiske, 1880, 154. 



The length of the head is to the total length nearly as 1 to 4, the extreme depth of the 

 body as 1 to 4|. Anterior part of the body deep, in the posterior region rapidly tapering; 

 tail at base long and slender. Upper jaw longer than lower. The dorsal tin originating 

 immediately above the branchial aperture; the caudal projecting to the extent of three- 

 tilths of its length beyond the dorsal and anal. Eyes small, their diameter being to the 

 length of the head as 1 to 7: interorbital space wide. The teeth exceedingly minute, 

 arranged in several series. Nostrils double. Pyloric appendages 10. 



Eadial formula: D. CO; A. 57; P. 11-12. 



Color a uniform bright red. (Collett.) 



A single specimen, 207 millimeters in length, was obtained by the North Atlantic 

 Expedition in the open sea between Beeren Eiland, Jan Mayen, and Finmark. 



