FUNDULUS. 77 
California and which probably enter the rivers of Sinaloa, and others which are not 
yet known to extend further south than the Rio Grande. 
Synopsis of the Mexican and Central-American Species. 
I. Origin of anal fin below or behind that of the dorsal. (Funputus.) 
A. 80 to 40 scales in a longitudinal series. 
1. Dorsal 12-14. Anal 13-17. Oviduct not produced into a tube attached to the anal fin. 
a. 82 to 85 scales in a longitudinal series. 
Interorbital width more than 4 the length of head; snout not longer thaneye. 1. pachycephalus. 
Interorbital width 4 the length of head or a little less ; snout not shorter 
thaneye . . . . 6 «© ss wee ew eee we eR punctatus. 
b. 36 to 39 scales in a longitudinal series . . .« . «~~. . . 98. labialis. 
2. Dorsal 10-13. Anal 10-12. Females with the oviduct produced into a tube or sheath 
attached to the anterior anal rays. (? J”. vinctus.) 
a. 31 to 34 scales in a longitudinal series. 
Interorbital width 4 the length of head, which is 3? in the length of the fish 
(in specimens of 65 mm.) . . woe ee ww we A vinetus. 
Interorbital width 2 the length of head, which is 32 in the length of the fish 
(in specimens of 70 mm.) . 5. pallidus. 
Interorbital width 4 the length of head, which is 3 | rea 1 the length of the fish 
(in specimens of 100mm.) . 2. ee ee ee ee ee eee 6 Stmilis. 
b. 35 to 39 scales in a longitudinal series. 
Anal fin deep, when laid back extending to or nearly to the base of caudal . 7. heteroclitus. 
Anal fin of moderate depth, when laid back not nearly reaching the caudal . 8. grandis. 
B. 44 to 60 scales in a longitudinal series. 
Dorsal 13. Anal ll. 44 scales in alongitudinal series . . . . . . © YQ. adinia. 
Dorsal 15. Anal 13. 47 scales in a longitudinal series . . . . . . «. 10. extensus. 
Dorsal 14-15. Anal 13-14. 60 scales in a longitudinal series . . . . . Ll. zebrinus. 
II. Origin of anal fin far in advance of that of the dorsal. (ZyGonrcrzs.). 12. dovii. 
1. Fundulus pachycephalus. 
Fundulus pachycephalus, Ginth. Cat. Fish. vi. p. 321 (1866)’, and Trans. Zool. Soc. vi. 1868, 
p- 483, t. 84. fig. 6 *, 
Adinia pachycephala, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 660°. 
Depth of body 3 to 33 in the length, length of head 3} to 34. Snout nearly as long as or shorter than eye, 
the diameter of which j is 34 to 3¢ in the length of head ; interorbital width more than 4 the length of 
head. Lower jaw slightly projecting. 32 to 35 scales in a longitudinal series. Dorsal 12 to 14; 
origin nearer to base of caudal than to head. Anal 13-15; origin below or a little behind that of the 
dorsal; no tube attached to the anterior rays. Pectoral 2 to = the length of head. Caudal subtruncate. 
Brownish, each scale with an indistinct darker spot; an indistinct dark lateral band on the posterior part 
of the body ; vertical fins dusky, the dorsal with a few spots, the anal with a pale margin. 
Hab. Guatemata, Lake Atitlan !? (Salvin). 
Here described from the types, four females measuring up to 72 mm, in total length. 
