DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 319 



DIPLACANTHOPOMA. BRACHYSOMA, GCntiier. 



Diplacanthopoma br'aclnjsoma, GiJNTHER, Challenger Report, xxu, 115, PI. xxill, tig. C; Alcock, Ann. and 



Mag. Nat. Hist., 1889, 385. 

 Siiemho miiniiiolepis, Vaillant, Exp. Sci. Travailleur et Talisman, Poissous, 1888, p. 273, pi. xxiii, tig. i, 4a. 



(Ott' Soudan). 



The greatest depth of the body is below the origin of the dorsal fin, aud contaiued twice 

 aud one-third in the distance of the extremity of the snout from the vent. The head is 

 about as deep as broad, its length being equal to the distance of the vent irom the root of 

 the ventral fius, and more than one-half of the length of the body exclusive of the tail. The 

 vent is nearer to the snout than to the root of the caudal. Eye of moderate size, without 

 orbital fold, as long as the snout, one-fifth of the length of the head and equal to the width 

 of the flat interorbital space. Mouth of moderate width, the maxillary extending somewhat 

 behind the eye and being slightly dilated behind. All the teeth are in narrow villiform 

 bands, that of the vomer being open and /^-shaped. The superficial bones of the head are 

 thin, and those of the infraorbital ring and of the mandible dilated for the reception of the 

 wide mucous canals. Of the opercular spines the horizontal is remarkably long, much 

 longer than the lower vertical one. 



The vertical tins arc completely united, and, owing to the great attenuation of the tail, 

 no caudal portion cau be distinguished. Tiie rays are very thin, closely set, and of mod- 

 erate length. Origin of the dorsal fin immediately behind the root of the pectoral, and 

 that of the anal immediately behind the vent. Pectoral fins rather narrow, inserted on a 

 short, broad, aud partly free i)edicle; they are longer than the postorbital portion of the 

 head ; ventrals half as long as the distance of their root from the vent. 



The scales are rather small, thin, cycloid, and rather deciduous; if a lateral line is 

 present, it is confined to the trunk. 



Upper parts of a uniform light brownish color; the lower parts aud the fins colorless. 



The type, i^ inches long, was taken by the Ghallcnyer oft' Pernambuco, Brazil (station 

 122), in 350 fathoms. Dr. Alcock has identified with the same species a fenuile l^ inches 

 long with gravid ovaries, taken by the Investigator in the Andaman sea, 7^ miles east of 

 North Cinque Island in 490 fathoms (=D. Alcockii, G. & B. See p. 523, below). 



DICROMITA, CooDE aud Bean, n. g. 



Brotulids resembling in form and general appearance Cata'tyx and Diaplacanthopojna, 

 having the lateral line obsolete, or interrupted posteriorly; ventrals a pair of simple, fine 

 filaments ; and teeth upon the palatines. It has, however, three or four small spines upon 

 the preoperculum, as well as a sharp spine upon the upper angle of the operculum; aud 

 the lateral line, though indistinct, is traceable for half or three fourths the length of the 

 body, which, like the upper part of the head, is covered with small, deciduous scales, the 

 opercular region being apparently scaleless, and the bones of the suborbital region almost 

 uncovered, with cons])icuous sinuses, which show through the transparent textiu-e of the 

 .surface. The head is oblong, the snout being somewhat produced, depressed and turgid, 

 resembling, though in a less degree, that of Barathrodcmus. Eye moderate, conspicuous. 

 M(nith wide; teeth villiform, in bands on the jaws and palatines, and very minute upon the 

 vonu'r, which has a roughencHl, knob like enlargement at its angle. Vent premedian. 

 Vertical fins confluent; ventrals rooted very close together, each reduced to a tine, flexi- 

 ble, simple filament, planted somewhat behind the isthmus and below the middle of the 

 operculum. Gills 4, with well developed lamin;^ aud rather long, slender giU-rakers. 

 Brauchiostegals 8. Pseudobrauchiie apparently absent. 



DICROMITA AGASSIZII, Goode and Be.vx, n. s. (Figure 285). 



Body elongate, much compressed, its height about one-fifth of its total length ; its 

 width about half its greatest height. The length of the head is slightly greater than the 

 height of the body, and equal to twice its own width. Mouth very large, the maxillary, 

 which is curved aud much dilated at its extremity, reaching far behind the vertical from 



