THE CYPRINODONTS. 49 
tion of the tail is short and high, its least depth being equal to the length of 
the head or to the distance between dorsal and caudal. The pectoral extends 
considerably beyond the root of the ventral, and the ventral reaches the origin 
of the anal. 
“Brownish olive, with a roundish black spot on the middle of the root of 
the caudal ; a blackish spot on the middle of the side of the trunk. Dorsal 
sometimes densely spotted with black ; the lower margin of the anal and the 
upper and lower margins of the caudal black.” 
Mexico. (Giinther). 
We have given above the original descriptions of genus and species. The 
specimens, two in number, were an inch and a half in length. Until more 
data are secured it will not be possible to determine the proper classification 
or affinities, 
MOLLIENISIA. 
Mollienisia Les., 1821, J. Phil. Ac., IT, 3; Val., 1846, C.V. Poiss., XVIII, 137; Blk., 1860, Cypr., 
482, 485, — 1863, Atl, III, 139. Molienesia Wagn., 1828, Isis, XXI, 1055. Molinesia Cuv., 1836, R. An., 
ed. 3, I, 533; Schinz, 1836, Nat. u. Abb., 217; Swains., 1839, Class., II, 190, 311; McCl., 1839, J. As. 
Res., XIX (2), 424; DeK., 1842, N. Y. Fish, 221; Poey, 1855, Mem., I, 382. Molinisea Swains., 1838, 
Class., I, 365. Mollinesia Stor., 1846, Syn., 182, —Mem. Am. Ac., II, 434; Ag., 1853, Am. Jour. Sci., 
XVI, 135; Jor. & C., 1877, B. Buf. Soc., IIT, 143. Mollienesia Ag., 1855, Am. Jour., XIX, 136; Gth., 
1866, Cat., VI, 347, — 1880, Intr., 617 ; Jor. & G., 1882, B. 16 U. S. Mus., 346. 
Body short, much compressed, caudal pedicel deep; head depressed 
crown flattened. Snout short, broad ; chin short, steep. Mouth wide, open- 
ing upward ; lower jaws short, weak, loosely joined ; upper shorter, protrac- 
tile. An outer series of slender, oar-shaped, hooked, movable teeth on each 
jaw, and behind these a band of small, pointed ones. Dorsal large, larger 
than anal, subject to considerable changes in males. Anal opposed to the 
dorsal, but usually originating farther back, modified in the male, as in Po- 
cilia, to form a short intromittent organ. Caudal region deep and narrow. 
Scales large, broad. Intestine long. Type MV. latipinna, 
Virginia to Central America. 
This genus is closely allied to Peecilia, with which it agrees in general 
form, dentition, structure of mouth, and modification of the anal fin. The 
principal characters on which to base a separation of these genera are the 
greater size of the dorsal and the greater changes effected by growth in 
Mollienisia. 
