ASTRONESTHIDAE 



307 



Described from a single specimen, 180 mm. in length. 



Hob. South Atlantic. 



In the form of the teeth on the maxillary this species is a typical Borostomias, but in 

 the anterior prolongation of the postocular luminous organ and in the structure of the 

 barbel it is very similar to some of the species placed in the genus Diplolychmis by 

 Regan and Trewavas. The single specimen is unfortunately poorly preserved, and it is 

 impossible to be certain as to the form of the postocular luminous organ. 



Fig. 15. Borostomias antarcticus. (x |.) [Barbel x il.] 



Neonesthes microcephalus, n.sp. 



St. 269. 26. vii. 27. 15° 55' 00" S, 10° 35' 00" E. 4J m. net, horizontal, 600-700 (-0) m. : 2 

 specimens, 145-148 mm. 



Depth of body nearly 7 in the length, length of head 6|. Snout short; diameter of 

 eye 4 in length of head. Postocular luminous body 3 to 4 in length of head, with a 

 narrow subocular prolongation more or less covered by a pigment layer. Barbel i^-q to 





Fig. 16. Neonesthes microcephalus. Holotype. (x f.) 



2\ times as long as head ; in the specimen with the shorter barbel the hyaline stem ends 

 in a swollen white bulb which is prolonged distally into a fine filament, and there is a 

 collar of pigmented tissue round the base of the bulb ; in the other specimen the hyaline 

 stem ends in a slightly swollen white tip, which is somewhat damaged but appears to be 

 without pigmented collar or filament. Dorsal 10, short, above interspace between 

 pelvics and anal. Anal 22 or 23. Pectorals 8. Pelvics 7-rayed, considerably nearer to 

 snout than to caudal. Traces of a ventral adipose fin. Photophores — in ventral series 

 I-P 9-10 ; P-V 16-17 ; V-A 18-19 ; A-C 12 (?) : in lateral series 0-V 14 (?) ; V-A 18 (?). 



Described from two specimens, 145 and 148 mm. in length, of which the smaller is 

 selected as the holotype. 



Hab. South Atlantic. 



