Ii2 
CC. 
e. 
f. 
ff. 
gs- 
aa. 
ii. 
i}. 
bh. 
Fretp Museum oF Natura History—Zo6tocy, Vor. X. 
Origin of dorsal slightly behind to well in advance of anal. 
Origin of anal under or slightly in advance of dorsal; origin of 
dorsal fin nearer tip of caudal than snout. 
Anal with a black blotch at base of anterior 5 rays to tip of third 
ray; dorsal rays 9 or Io. Priapichthys olomina. 
Anal without dark blotch at base of anterior rays; dorsal rays 
10 to 12. Priapichthys annectens. 
Origin of anal below middle of dorsal; dorsal rays 11 or 12; an 
interrupted dark lateral stripe. | Pseudoxiphophorus terrabensis 
. Origin of anal below anterior fourth of dorsal; origin of dorsal 
nearer tip of snout than end of caudal. 4 
A series of short, dark, vertical bars along the middle of the side; 
dorsal with 2 or 3 series of dark spots. 
Brachyrhaphis rhabdophora. 
A few faint, narrow, dark bars on posterior half of body; basal 
third of dorsal black. Brachyrhaphis umbratilis. 
Dentary bones not firmly united, teeth movable; alimentary 
canal longer than the body. 
Origin of the dorsal fin nearer tip of caudal than end of snout. 
Origin of dorsal behind that of anal, nearer tip of caudal than 
end of snout, midway between anterior margin of eye and tip 
of caudal fin; origin of anal in advance of dorsal; anal rays ro. 
Pecilopsis retropinna. 
Origin of dorsal over or before that of anal. 
Origin of dorsal midway between base of caudal and anterior 
margin of the eye; modified anal of the male twice the length of 
head. Peciliopsis pittiert. 
Origin of dorsal midway between base of caudal and middle of 
opercle; scales with darker centers; modified anal of male short, 
its length less than that of head. 
Base of dorsal rays without definite black spot; dorsal rays 9 to 
11, the free edge convex. Mollienisia sphenops. 
. A black spot at base of dorsal rays; dorsal rays 8 or 9; free edge 
of dorsal straight or slightly convex. Mollienisia s. tropica. 
Origin of dorsal midway between end of snout and posterior edge 
of caudal fin, behind that of anal; anal rays 8. 
Mollienisia elongata. 
Alfaro Meek. 
Petalosa Regan, Ann, & Mag. Nat. Hist., 1908, 458 (type Petalosa 
cultratum Regan). 
