106 . HAPLOMI, 
the fin, below which are longitudinal stripes and above which are numerous smaller spots; caudal with 
series of small spots. 
Hab. South Carolina to Tamaulipas : 
Pensacola in Florida; New Orleans! °®; Indianola’ and Brownsville’ in Texas ; 
Matamoros 1°, Palo Alto®, La Vega®, and Tampico ° in ‘Tamaulipas. 
Here described from several specimens, measuring up to 75 mm. in total length, 
from New Orleans, Pensacola, and Tampico. Garman’s plate illustrates strikingly 
the differences between the sexes and the changes during growth in this species, 
which attains a length of 100 mm. 
2. Mollienisia petenensis. 
Mollienisia petenensis, Giinth. Cat. Fish. vi. p. 348 (1866) ', and Trans. Zool. Soc. vi. 1868, p. 485, 
t. 86. figs. 1-3°; Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 700°. 
Depth of body 22 to 3 in the length, length of head 4. 28 to 30 scales in a longitudinal series. Dorsal 15-16. 
Anal 9. Caudal rounded or subtruncate, in the males with the lower angle pointed and slightly 
produced. Males with a small dark spot on each scale of the upper and posterior parts of the body and 
with the lower edge of the caudal blackish ; dorsal fin coloured as in M. latipinna. 
Hab. Guatemata, Lake Peten (Salvin) 1 ?. 
Here described from the types, six specimens, measuring up to 130 mm. in total 
length. This species is very close to the preceding, but it attains a larger size and is 
distinguished by the form of the caudal in the males, which suggests relationship with 
Xiphophorus. 
. 15. XIPHOPHORUS, Heck., 1848. 
AXiphophorus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 701. 
Scarcely generically distinct from Peweilia and Mollienisia. Dorsal with 11 to 15 rays, higher but not much 
longer in the males than in the females. Males with the lower rays of the caudal fin produced to form a 
long pointed appendage. 
Hab. Tamaulipas to British Honduras. 
The five closely allied species of this genus agree in the following features :—Snout 
as long as or a little shorter than eye, the diameter of which is 3 to 34 in the length 
of head, interorbital width 12 to 14. Origin of dorsal about equidistant from tip of 
snout and base of caudal, well in advance of that of the anal (¢@). Pectoral nearly as 
long as the head. Caudal appendage of the males pale, with black edges. 
Synopsis of the Species. 
J. Anal with6to8rays . 2. 2. 1 1. we ee eee ee ee ee dL montezume. - 
IJ. Anal with 8 to 10 rays. 
A. Depth of body 3-4 in the length. 
1. Least depth of caudal peduncle not greater than the distance from 
anteridr margin of eye to free edge of operculum . . . . . . . 2. helleri. 
