POLYPTERUS. — CALAMICHTHYS. ' 17 



10. POLYPTERUS RETROPINNIS. 



Vaillant, Bull. Mus. Paris, 1899, p. 219; Bouleng. Poiss. Bass. Congo, p. 26 

 (1901). 



Body siibcylindrical. Head 1 J times as long as broad, 5f to 6| times 

 in total length, with lateral eyes and convex interorbital region ; snout 

 projecting beyond lower jaw ; eye 6 J to 8 times in length of head, 2 to 

 2J times in interorbital width ; head-shields all paired ; suboperculum 

 smaller than eye. Dorsal with VI- VII spines, widely separated when 

 folded. Anal 12-15. Pectoral widely separated from first dorsal spine. 

 58-59 scales in a longitudinal series, 35-37 between occiput and first 

 dorsal spine, 32-36 round middle of body. Olive-grey above, whitish 

 beneath ; more or less distinct darker cross-bands on the back ; a black 



Fi?. 12. 



Pohjpterus retropinnis. 

 Type (in Paris Museum). |. 



spot sometimes present on the membrane behind each dorsal spine ; 

 more or less distinct dark streaks across rayed part of pectoral tin, and 

 a large black spot on its muscular part. 



Total length 230 millim. 



Alima River, Upper Congo — Types in Paris Museum. 



1. One of the types. Alima R. M. J. de Brazza (0.) ; 



Paris Museum (E.). 



2. CALAMICHTHYS. 



ErpetoicUliys (non Swainson), J. A. Smith, Proc. Phys. Soc. Edinb. 1865, p. 273. 

 Calamoichthys, J. A. Smith, Proc. R. Soc. Edinb. v. 1866, p. 655 ; A. Dum. 



Hist. Poiss. ii. p. 397 (1870) ; Glinth. Cat. Fish. viii. p. 327 (1870) ; Bouleng. 



Poiss. Bass. Congo, p. 27 (1901). 



Body much elongate, cylindrical, serpentiform. Spines of dorsal fin 

 supporting a single articulated ray. No ventral fins. Suboperculum 

 very small or absent. Teeth small, conical. 



West Africa. 

 VUL. I. c 



