->9 



:moemyrid^. 



4. PETROCEPHALUS BALLAYI. 



Mormi/ria^ cafosioma (non Giintli. 18(Jt)), Giintli. Ann. k Mao-. N. H. (.'V) xx. 1867, 



p. i(;n. 



Pefrocepludus halat/i, Sauv. Bull. Soc, Pliiloni. (7) vii. 1883, p. 159 ; Bouleng. 



Proc. Zool. Soc. 1898, p. 780, and Poiss. Bass. Congo, p. 72 (1901) ; Pellegr. 



Bull. Soc. Philom. (9) ix. 1907, p. 20. 

 Mo)')7ii/rus arnhJi/stonia, Giinth. Ann. & Mag. N. H. (G) xvii. 1890, p. 281, 



pi. xiv. fig. A. 



Depth of body 2 J to 3 times in total length, length of head 3 J to 

 3| times. Head as \or\g as deep, with convex upper profile ; snout very 

 short, ^ to 5- length of head, obliquely truncate, projecting beyond mouth ; 

 mouth below anterior border or centre of eye, its width ^ length of head ; 

 teeth bicuspid, 20-24 in upper jaw, 30-36 in lower; nostrils above 

 lower border of eye ; eye large, its diameter greater than length of 

 snout, § interorbital width. Dorsal 21-20, originating above 4th or 5th 

 ray of anal, its length nearly ^ its distance from head and equal to its 



Fig. 37. 



^'\ 



2'^-'-i.i^^Q£i. 



Petroccphahts haUai/i. 

 Type of ^f. ambhf stoma, after (Uiuther (Ann. & Mag. N. II. 1896). 



distance from caudal. Anal 28-30, slightly nearer base of caudal than 

 base of ventral. Pectoral pointed, | length of head. If length of 

 ventral, extending beyond base of latter. Caudal scaled at the base, 

 with pointed lobes. Caudal peduncle 2h to 3 times as long as deep, 

 f to f length of head. 35-37 scales in lateral line, jj^j^ in transverse 

 series on the body, -^ in transverse scries between dorsal and anal, 



