go FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. III. 



rakers long and slender, 35 to 40 on the first gill-arch. Vertebrae 

 19-1-17 = 36. GOODEA. 



nn. Body deep, compressed, depth 2| to 3^ in length. Gill- 

 rakers rather short, stiff, about 20 the first gill-arch. Vertebrae 

 i6-f-i8 = 34. SKIFKIA. 



mm. Outer series of teeth pointed; anal fin of the male placed 

 well forward and modified into an intromittent organ. Species vivip- 

 arous. (Poecelinae. ) 



o. Teeth in a single series. 



p. Dorsal fin inserted in advance of the anal. . PLATYPCECILUS. 



//. Dorsal fin inserted more or less behind the front of the anal. 



oo. Teeth in more than one series. HETERANDIA. 



/-. Dorsal fin inserted more or less behind the front of the anal; 

 both fins small: dorsal 9, anal 7. LEBISTES. 



rr. Dorsal fin inserted over or in advance of anal, its rays much 

 elevated in the male. 



s. Dorsal fin short of less than 7 to 1 1 rays. 



t. Teeth of inner series in both jaws trifid. /EROPO-:CILUS. 



//. Teeth of the inner series in both jaws entire. }><KCII.IA. 



ss. Dorsal fin long, of 12 to 16 rays. 



//. Caudal fin normal, alike in both sexes, or with the lower 

 angle merely sharp in the male. MOLLIENISIA. 



////. Caudal fin in the males with its lower lobe much produced 

 and sword shaped. XIPHOPHORUS. 



FUXDULUS Lacepe"de. 



This genus does not have many representatives in Mexico. It is 

 probable that some of the species found in Southwestern Texas, 

 especially those species which are peculiar to the lower Rio Grande 

 basin, extend their range into Mexico. 



In this genus the anal fin of the males is like that of the females. 

 Teeth firm and in more than one series. The alimentary canal is less 

 than i i times the length of the body. Species all oviparous. 



Fundulus oaxacae, sp. nov. 



Type, No. 3721, F. C. M. Length, 2.25 inches. 



Locality, Rio Verde, Oaxaca, Oaxaca, Mexico. 



Head 3|; depth 3^: D. 14: A. 15; Scales 30-11. Body robust, 

 profile from nape slightly concave: top of head broad, slightly 

 convex: eye small. 4^ in head: snout not much depressed, 

 3ji in head: interorbital space 2l; lower jaw slightly the longer; 

 teeth pointed, in a band in both jaws, the outer series the 



