280 CHAEACINID^. 



Ventral fins very small 29. Gastropelecus, p. 342. 



Intermaxillary teeth in a single series ; ventral fins well developed. 



30. PiABucA, p. 343. 



*** Belly compressed ; canine teeth in the lower jaw. 

 A part of the teeth only are tricuspid 31. Agoniates, p. 344. 



/3. All the teeth are conical (Htdeoctonina). 



* No teeth on the palate ; anal fin long. 



Dorsal fin behind the ventrals ; scales small 32. Anacyrtus, p. 345. 



Dorsal fin above the ventrals 33. Hystricodon, p. 349. 



Dorsal fin behind the ventrals ; scales of moderate size. 



34. Salminus, p. 349. 



** No teeth on the palate ; anal fin of moderate length. 

 Dorsal fin above the ventrals 35. Hydrocyon, p. 350. 



*** A series of teeth on each side of the palate, which are implanted 

 on a process of the intermaxillary, and not on the palatine 

 bone. Anal fin short. 

 Dorsal fin behind the ventrals 36. Sarcodaces, p. 352. 



**** Each palatine bone with a series of conical teeth ; anal fin long. 



Dorsal fin in the middle of the length of the body ; scales of moderate size. 



37. Oligosarcus, p. 353. 



Dorsal fin behind the middle of the length of the body ; scales small. 



38. XiPIIORHAMPHUS, p. 353. 



***** Each palatine bone with a patch of minute granular teeth. 



Anal short ; belly rounded 39. Xiphostoma, p. 356. 



Anal long ; beUy compressed 40. Cynodon, p. 358. 



b. Dorsal fin rather elongate. 



aa. Gill-openings of moderate width, the gill-membranes being 

 attached to the isthmus (Distichodontina). 

 Belly rounded 41. Distichodus, p. 359. 



bb. Gill-openings tvide, the gill-membranes not being attached 

 to the isthmus. 

 n a. Belly rounded ; jaws with conical canine teeth (Ichtht- 

 borina). 

 Lateral teeth of both jaws compressed, triangular. 42. Ichthyborus, p. 362. 



/3. Belly rounded ; canine teeth none (Ckenuchina). 

 Both jaw6 with a single series of tricuspid teeth... 43. Crenuchus, p. 365. 



y. Belly with a spinous serrature (Sekeasalmonina). 

 Intermaxillary teeth tlu-ee-lobed, in two series ... 44. Mylesinus, p. 366. 



Intermaxillary teeth with lateral lobes, in a single series. 



45. Serkasalmo, p. 366. 



Intermaxillary teeth with a more or less oblique cutting edge, in two series. 



46. Mylbtes, p. 372. 



Intermaxillary teeth conical, in two series 47. Catoprion, p. 379. 



(ArPENDI.X, p. 379.) 



