CYPKINID^. — XXVI. 51 



d. Teeth 5-5 or 4-5; dorsal inserted behind ventrals; scales very small; 

 anal short. 

 e. Fseudobranchias none; lower jaw thin, with sharp, hard edge; upper 

 jaw protractile, with fleshy covering ; lateral Hue con)plete; body 



elongate, subterete Oxygeneum, 50. 



ee. Pseudobranchia; present; lips thin, normal; upper jaw protractile; 



lateral line incomplete Chkosomus, 51. 



dd. Teeth 4-4; pseudobranchiaj present; dorsal over ventrals; scales 

 rather large. 

 /. First (rudimentary) ray of D. slender, firmly attached to the first de- 

 veloped ray; jaws sharp-edged, the lower with a sliglit projection in 

 front; scales before D. large (less than 15). Hybognathus, 52. 

 j^. 1 First (rudimentary) ray of U. well developed, bluntish, separated 

 from the first developed ray, to which it is joined by membrane 

 (this character never conspicuous except in adult males; often ob- 

 scure in young); scales before D. small (more than 20.) 



PiMEPHALES, 53. 



CC. Alimentary canal short, less than twice length of body; teeth hooked, 

 the grinding surface, if present, narrow and rudimentary; peritoneum 

 usual)}' pale ; species mostly carnivorous. 

 g. Dentary bones parallel, united for their whole length (the lower jaw- 

 reduced to a tongue-like projection, which has a fleshy lobe on each 

 side. (F.xoglossina:.) 

 h. Premaxillaries not protractile; upper lip thickened; scales moder- 

 ate ; teeth 1, 4-4, 1, without grinding surface. Exoglossum, 54. 

 gg. Dentary bones broadly arched, as usual among fishes, and united 

 only at the symphysis. {Leudsdnm.) 

 i. Abdomen behind V. not compressed to an edge, the scales passing 



over it; anal basis generally short (the rays 7 to 12). 

 j. Teeth in tlie main row, 4-4. 

 Ic. Maxillary without traces of barbel. 

 X. [Premaxillaries protractile.] 



I. Lower lip thin or obsolete (except in one or two species), not 



developed as a fieshj' lobe on each side. 

 m. Mandible, interopercle, and suborbital not evidently cavernous. 

 n. 1 First (r\idimentary) ray of D. enlarged and bluntish, sepa- 

 rated from the first developed ray by membrane (as in Fime- 

 phales), this most evident in 6 ; scales before D. small, 

 about 28; teeth 4-4; [black blotch on front of dorsal and 

 one at base of caudal always present.] . . Cliola, 55. 

 nn. First (rudimentary) ray of D. small, closely joined to the 

 first developed ray; teeth 2, 1 orO, 4-4, 2, 1 or 0; scales 

 rather large; scales before D. large or small (12 to 30). 



NoTRoris, 56. 

 mm. Mandible, interopercle, and suborbital with conspicuous 

 externally visible cavernous areas (like silverj' cross- 

 bars); teeth 1, 4-4, 0; scales large; D. above V. 



P'UICYMBA, 57. 



II. Lower lip developed as a fleshy lobe on each side ; teeth 4-4, 



■without grinding surface; D. before V. ; isthmus very broad. 



PHENACOBIUS, 58. 



1 This character is more or less obscure in females and young examples. 



