194 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



Subfamily THYRSITIN^E. 



Scombrids with elongate, subfusiform, more or less compressed bodies, and long spin- 

 ous dorsal. Finlets present or absent. Ventrals sometimes reduced to a single spine. 

 Pectorals comparatively low. Caudal not carinated. Pyloric caeca rather few. 



THYRSITES. Cuv. & Val. 



Thyrsites, Cuv. and Val., Hist. Nat. Poiss. vm, p. 196.— Gill. Proc. Acad. Nat. Sci., Phila., 1862, p. 126. 



Body fusiform and rather elongate. First dorsal with less than 25 spines. Pectorals 

 equidistant from the back and breast. Teeth on the palatines. Spinous dorsal contiguous 

 to the soft, variable. Pectorals equidistant from the back and breast, or nearer the latter. 

 Tail not keeled. Ventrals I, 5. Dorsal and anal unlets developed. Lateral line present. 

 Dorsal and anal finlets (i. Lateral line abruptly declined behind the last spines. 



No species of this genus as modified by Gill has been found in the North Atlantic, but 

 since it occurs in South African waters it is likely to occur farther to the north and the 

 diagnosis and figures are introduced for comparison. 



Tkyrsites atun (Euphrasen) C. and V., is the only species. It is undoubtedly a deep- 

 water form. 



THYRSITOPS, Gill. 



Thyrsitops, Gill, Proc. Acad. Nat. Sci. Phila., L862. 



Body fusiform, rather elongate. First dorsal with less Mian 25 spines. Spinous dorsal 

 contiguous to the soft dorsal fin. Pectorals equidistant from the back and breast, or nearer 

 the latter. Tail not keeled. Ventrals I, 5. Dorsal and anal finlets developed. Dorsal finlets 

 5, anal 4. Lateral line nearly straight. 



THYRSITOPS LEPIDOPOIDES, CuviER and Valenciennes. 



Thyrsites lepidopoides, Cuvier and Valenciennes, Hist. Nat. Poiss., viii, 205, pi. cexx. — Gunther, Cat. Fish. 



Brit. JIus., ii, 350. 

 Thyrsitops lepidopoides, Gill, Proc. Acad. Nat., Sci., Phila., 1862, 126. 



A Thyrsitops with a somewhat robust body, having its height one-sixth of its total 

 length, its thickness two-fifths of its height. The lengi h of the head, as in pretiosus, is one- 

 fourth of the total length. Nostrils so placed that the anterior is midway between the orbit 

 and the tip of the snout, and the posterior midway between the anterior and the orbit. 

 Lower jaw passing the upper, but obtuse. Teeth in the jaws small, those in the roof of the 

 mouth anteriorly very large and conspicuous. A row of teeth on the vomer, and another 

 along each palatine bone, small, short, and sharp. Tongue smooth. Operculum deeply 

 emarginate, having two sharp points, flexible, intruding into the skin. First dorsal low, 

 uniform in height, 17 very flexible rays, the length of which is about one fourth of the 

 height of the body, the last being very small. The length of the base of this fin is one- 

 third that of the body. The second dorsal in its anterior part is twice as high as the first, 

 and its length is twice its own height. It is composed of 2 hidden spines and 14 rays, and 

 is followed by 4 finlets. The anal is similar to the second dorsal in position and size, is 

 composed of 2 spines and 15 soft rays, and is followed by 4 finlets, the last of which 

 looks as if it were double. The length of the pectoral is one-ninth of the total length. 

 Ventral two-thirds as long as the pectoral. The head and the most of the body appear 

 to be smooth, but toward the end of the tail some scales are visible. The lateral line is 

 nearly straight, and formed of a series of little, serrated scales. Color silvery, a little 

 darker on the back; the lateral line brown, fins gray, iris golden. 



Radial formula : D. XVII, II, 14+IV; A. II, 15+IV. 



The types of this species were sent to the Muse~e d'Histoire Naturelle from Brazil by 

 Delalande, and were a foot in length. The species is undoubtedly an inhabitant of consid- 

 erable depths. 



