346 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
5C5. O. nfliiiis (B. & G.) Grd. 
Body luodcratcly stout. Dorsal and anal fins similar in size and 
shape, the latter not much advanced. Coloration plain; dorsal and 
caudal dotted with black. Dead 4; depth 3-|-. D. G; A. 8. Texas. 
{Girard.) 
{llctcrandria affinis B. & G. Proc. Acad. Nat. Sci. Phila. 1853, 390; Girard, U. S. 
Mex. Bound. Stirv. Iclith. 72; Giiuther, vi, 330.) 
* O. B. & G.* 
Body very deep, elevated in front of dorsal. Anal much smaller 
than dorsal. Veiitrals very small. Coloration plain. Uead 3^; depth 
3^. D. 8; A. 7. L. 2.| inches. Texas. {Girard.) 
(Ilefcrandria uobilis B. & G. Proc. Acad. Nat. Sci. Phila. 1853, 390; Girard, U. S. 
Iklox. Bound. Surv. Ichth. 71; Gunther, vi, 335.) 
(Two other species from the Rio Grande region, G. spcciosa and G. senilis, are briefly 
and probably unrecognizably described by Girard, Proc. Acad. Nat. Sci. Phila. 1859, 
121 ). 
162 .— ITIOJLI.aEl\ESIA Le Sueur.t 
{Limia Poey.) 
(Lo Sueur, Jonru. Acad. Nat. Sci. Phila. ii, 1821, 3: type Mollienesia latipinna Le 
Sueur.) 
Body rather stout. Mouth small ; mandible very short, its bones not 
united, the dentary being movable; both jaws with a narrow band of 
small teeth, besides an enter series of long, slender, movable teeth, 
which are curved and slightl}’^ compressed, placed on the outer edge of 
the jaw. Branchiostegals usually 5. Scales rather large. Anal fin 
* G. gracilis (Hcckel) Gthr. 
Anal i^rocess twice as long as head ; the extremity bent. A dark band from upper 
end of gill-opcuing to the caudal. Head 4; depth 4. D. 8; A. 9; scales 29-7. Ori- 
zaba, Mexico. {Gunther.) 
{Xijdiophorus gracilis Heckel, Sitzgsber. Akad. Wiss. Wien, 1848, i, pt. 3, 300 ; Giin- 
ther, vi, 33G.) 
tXIPHOPHORUS Heckel. 
(Heckel, Sitzgsber. Akad. Wiss. Wien, 1848, i, pt. 3, 1G3: type Xiphophorus liellcri 
Heckel.) 
This genus differs from Mollienesia chiefly in the structure of its caudal fin, the lower 
rays of which in the males are prolonged into a long sword-shaped appendage, which 
in the adult is sometimes as long as the rest of the fish. Anal of the male modified 
into au intromittent organ, one or two of the enlarged rays being provided with hook- 
like pi’ocesses. Bianchiostegals 5. sword ; to bear.) 
X. hellad Hcckel. 
Sides with blue and yellowish-green bands or dark spots. Prolonged caudal ap- 
pendage of the male nearly as long as the body, yellow, with black edges. Anal pro- 
cess with numerous hooks. Head 4^; depth 3J. B. 5; U. 13; A. 9; scales 29-8. 
Mexico. (GUnther.) 
(Heckel 1. c. ; GUnther, vi, 349.) 
