188r,.] PROCEEDINGS OF UNITE b STATES NATIONAL MUSEUM. (j()5 



is 183 millimeters long to caudal base, 215 with caudal. Another speci- 

 men is numbered Blake, XCV, off Dominica, 330 fathoms (juv.) ; this is 

 70 millimeters long. 



Description : Body moderately elongate, much compressed, the tail 

 much shorter and more robust than in B, catena. Its height (26™'") 

 equals 1^ times the length of the head and one-seventh that of the body. 



Head stoutish, not much compressed, lower than body, its length 

 (34™°") contained 5^ times in the body length. Snout compressed, broad 

 at its tip, its length (6™™) exceeding the diameter of the circular eye 

 (5'"™). Interorbital area slightly convex, its width (11""") slightly exceed- 

 ing twice the diameter of the eye, 3 times in length of head. 



Maxilla extending far behind the eye, its length (19'""') less than that 

 of i>reorbital portion of head. Mandible as long as i)ostorbital portion 

 of head (22"^"^). Jaws, vomer and palatine, with narrow bands of villi- 

 form teeth, normally arranged. Branchiostegals 8. Gill-lamellae very 

 short, (jrill-rakers long and numerous, 18 on tirst arch below the. angle, 

 5 above, 4 of which are rudimentary. Pseudobranchiae present, but 

 very rudimentary. 



Anterior nostrils on the top of the snout and near the median line 

 of the head, near its tip, separated by a space about equal to the diam- 

 eter of the eye. Posterior nostrils in front of the eye. 



Muciferous pores large, arranged much as in B. catena. 



Dorsal origin in the same vertical with that of the pectorals, its dis- 

 tance from the tip of the snout (38°"") contained 5 times in total and 

 equaling twice the length of the maxilla. Eays well developed in the 

 anterior third, the longest two-thirds of head's length. 



The anal origin is under the twentieth dorsal ray ; its rays are nearly 

 as long as those of the dorsal. The pectoral has its penultimate ray pro- 

 duced, extending to the thirteenth ray of the anal ; it is nearly twice as 

 long as the head. Ventrals bifid, originating in advance of the vertical 

 through the pectorals. Distance of the ventral origin from tip of snout 

 (26™™) equaling length of ventral and about three-fourths as long as the 

 head. Distance of origin of ventral from vent (42™™) considerably greater 

 than length of head. Distance from tip of ventral to vent equal to half 

 the length of the head. 



Numbers of scales in transverse series from vent to dorsal about 23 ; 

 from the upper angle of the gUl-opening to the vertical through origin 

 of anal, 32. 



Color, brownish yellow. Head and abdomen blackish. 



D. 93; A. 73; P. 17; V. 2. 



This species seemis closely related to Bathyonus laticeps (Gthr.), but 

 differs in several important particulars, notably the prolongation of the 

 pectoral ray and the form of the tail. 



