CEOMERIA. 173 



Fam. 10. CROMERIID.E. 



Margin of the upper jaw formed by the pragmaxillaries and the 

 maxillaries ; mouth not protractile, inferior, toothless ; supraoccipital 

 large and widely separating the very small parietals ; opercular bones 

 well developed ; symplectic absent. Gill-opening very narrow. Body 

 naked. Ribs sessile. Pectoral fin inserted low down, folding like the 

 ventrals. No postclavicle. 



A single genus. 



1. CROMERIA. 

 Bouleng. Ann. & Mag. N. H. (7) viii. 1901, p. 445, and Fish. Nile, p. 93 (1907). 



Mouth small and toothless, inferior. Gill-opening very narrow, 

 lateral ; 3 branchiostegal rays. Body elongate, compressed. Dorsal 

 and anal fins short, on the caudal portion of the body. Vertebra? 42-45 

 (28-30 + 14-15). Air-bladder long and slender, extending along the 

 whole praecaudal part of the body. 



White Nile. 



1. CROMERIA NILOTIC A. 

 Bouleng. 11. cc. pp. 445, 94, pi. xiv. fig. 3 ; Swinnerton, Zoo!. Jahrb., Anat. xviii. 

 1903, p. 58, figs. 

 Depth of body C^ to 8 times in total length, length of head 5 to 6 

 times. Snout rounded, projecting strongly beyond mouth, the width 

 of which is about 6 times in length of head ; diameter of eye about 

 5 times in length of head. Dorsal 9-10, 3 or 4 rays rudimentary, 



Fig. 137. 



Cromeria nilotica. 

 Type, x 2. 



5 branched, opposite to the space between ventrals and anal, about 

 twice as distant from end of snout as from base of caudal ; longest 

 rays f to f length of head. Anal 9-10, 3 or 4 rays rudimentary, 

 5 branched, similar to the dorsal, nearly equally distant from ventrals 

 and from base of caudal. Pectoral f or -f as long as head, longer than 



