Classification of the Order Ostariophysi. 15 



Cypvinoids are malacopterous physostoraes * with the pelvic 

 fins, wlien present, abdominal ; the head is naked and the 

 body is usually scaly ; the branchiostegals are few, 3-5. 

 Parietal bones are present, either meeting in the middle line 

 or separated by a fontanel, and an orbitosphenoid is always 

 present ; the raetapterygoid and symplectic are well deve- 

 loped ; most of the parapophyses are distinct from the centra 

 (except in Misgurnus) and the anterior vertebrae remain 

 separate, or only the centra of the second and third may 

 unite ; epipleurals and epineurals are present. 



The suborder Cyprinoidea includes three well-marked 

 divisions — Characiformes, Gymnotiformes, andCypriniformes. 



Division 1. CuARACIFOEMESt. 



Body deep or moderately elongate ; dorsal and caudal fins 

 well developed ; pelvic fins present ; usually an adipose fin. 

 Mouth typically non-protractile; jaws usually toothed and 

 maxillary rarely excluded from the gape. Upper and lower 

 pharyngeals dentigerous, normally opposed. An opisthotic ; 

 posterior temporal fossai well developed, with two or three 

 posterior apertures. Hyopalatine and opercular bones all 

 present ; palatine firmly attached to pterygoid and meso- 

 pterygoid. Post-temporal forked. Air-bladder large, free, 

 divided into two by a transverse constriction. 



This group comprises several hundred species from the 

 fresh waters of Central and South America and Africa ; it 

 corresponds to the family Characidae or Characinidoe of 

 authors |. 



Family 1. Characidae. 



Prgemaxillaries not much produced ; inaxiliaries well 

 developed. Teeth in jaws usually strong; palate sometimes 

 toothed. Hyomandibular two-headed, tlie posterior head 

 inserted in a groove of the pterotic, the anterior with flat or 

 concave surface articulating with a fl.it or convex surface on 

 the sphenotic ; pterygoid narrowed posteriorly, immovably 

 attached to quadrate or mesopterygoid. Orbito-sphenoid 



* Many Cobitidse and Homalopfceridte, with the air-bladder reduced 

 and encapsuled, are physocUsta. 



t Sagemehl, Morph. Jahrb. x. 1885, p. 102, has written a valuable 

 memoir on the crauial osteology. Gill, Proc. U.S. Nat. Mus. xviii. 1895, 

 p. 205, gives a list of some other papers of lesser importance. 



X Cf. Bouleng. Camb. Nat. Hist., Fish. p. 575 (1!)04), and Cat. Afr. 

 Freshwater Fish. i. p. 174 (1909) ; Eigenmann, Keports Princeton Exped. 

 Patagon. iii. Zool. pts. 3 (1909) & 4 (1910). 



