2518 Bulletin 4.7, United States National Museum. 



equal in length, though the tip of the tail is slightly rounded, about equal 

 to height of body midway between branchial opening and base of tail ; 

 ventrals inserted almost under middle of operculum, in length about 

 equal to \ length of head; pectorals inserted under origin of dorsal, and 

 at a distance behind branchial opening equal to vertical diameter of 

 eye, its length equal to greatest height of the body. Color grayish 

 brown; abdominal region black. (Goode & Bean.) Gulf stream, north 

 of the Bermudas, in 647 to 1,395 fathoms. (Manati, like the manatee or 

 sea cow.) 



Barthrodemus manatinus, GOODE & BEAN, Bull. Mug. Comp. Zool., x, No. 5, 200, 1883, 

 Lat. 33 35' 20" N., Long. 76 W., in 647 fathoms (Type in M. C. Z. Coll. Slake); 

 JOBDAN, Cat., 127, 1885; GUNTHER, Challenger Keport, xxii, 100, 1887 ; GOODE <fc BEAN, 

 Oceanic Ichthyology, 332, fig. 294, 1896. 



967. NEMATONUS, Gimther. 



Nematonus, GUNTHER, Challenger Report, xxn, 114, 1887 (pcctoralis) . 



Body compressed, with long tapering tail. Bones of head soft, mucif- 

 erous channels moderately developed, and with the integument very thin 

 or absent on the upper portion and snout. Operculum cartilaginous and 

 flat ; a broad process near its upper angle corresponding to the opercular 

 spine in some of the related genera, the head otherwise unarmed, though 

 irregular by reason of the cranial bones. Snout much depressed, broad, 

 rounded; jaws equal in front; mouth very wide; bands of villiform teeth 

 in jaws, on vonier and palatines. Barbel none. Eyes small. Vertical 

 fins confluent; ventrals a pair of bifid filaments close together, on the 

 isthmus, close to the humeral symphysis. Gills 4, with very short laminai 

 and rather short, incurved, acicular gill rakers on the first arch, and much 

 shorter, less numerous, spatulate ones on the 3 other arches. Pseudobran- 

 chise rudimentary. No traces of a lateral line, though the body is covered 

 with scales of considerable size, almost as large as the eye, and the cheek 

 with others still larger. Nematonus differs from Poroyadus not only in the 

 absence of spines upon the head, as Gunther has indicated, but in the 

 much less ossified opercular apparatus, in the shorter and thicker head, 

 in the absence of the 3 series of pores simulating lateral lines, and in the 

 tendency to prolongation in the lower rays of the pectoral, which increase 

 from the uppermost to the lowermost in Nematonus, while Porogadus has 

 a lanceolate fin, and also in the extreme exsertion of the caudal rays. 

 (vijjua, thread; Onus, the rockling.) 



2890. NEMATONUS PECTOBALIS, Goode & Bean. 



D. 93 ; A. 73 ; P. 17 ; V. 2. Body moderately elongate, much compressed, 

 the tail much shorter and more robust than in Bassozetus catena, its height 

 equaling 1$ times length of head and f that of body. Head stoutish, 

 not much compressed, lower than body, its length contained 5^ times in 

 the body ; snout compressed, broad at its tip, its length exceeding diame- 

 ter of the circular eye; interorbital area slightly convex, its width 

 slightly exceeding twice diameter of eye, 3 times in head. Maxillary 



