May, igo2. The Ichthv(il()(;v ok Mexico — Mf.kk. 105 



A second female, 1.54 inches in length, contained 10 young, 

 each .45 inch in Itngth. 



A third specimen, 2.15 inches in length, contained 25 young, 

 each .55 inch in length. These specimens were collected at 

 Zirahuen, I\Iay 24. Spawning time for this species about the 

 middle of May. This is the smallest species of the genus. 

 Zirahuen; Chalco. 



Skiffia bilineatus Bean. 



A few specimens from Huingo. Longest female, 1.60 inches 

 in length. One female, 1.50 inches in length, contained 27 young, 

 which were very slender, white, and .32 inch in length. Col- 

 lected May 26. 



Dorsal fin of males much higher than that of females. Pos- 

 terior half of lateral band broken into 12 to 15 short irregular 

 bars, a few of which extend almost to the dorsal tin. The upper 

 half of the body has a few fine punctulations. The male is more 

 slender than the female. Longest male, i.io inches. 



Spawning time about third and fourth weeks in May. 



Alimentary canal slightly less than 2I times the total length 

 of body. Peritoneum black. The teeth are bicuspid and less 

 firm than in other species of Skiffia. 



Dorsal in advance of anal fin, its origin midway between base 

 of caudal and middle of opercle. Huingo. 



KEY TO THE SPECIES t)F SKIFFLA. 



a. A black bar. at base of caudal (inconspicuous in some males 

 of /enim, which have a uniform coloration and a very dark head). 



/'. Body light olivaceous in females, mottled with dark, nearly 

 plain on lower half of body; males nearly plain; head usually quite 

 dark; D. 13; A. 14; scales 37-14. ],i:r.m.i<;. 



i>i>. Light olivaceous \n females, a dark spot on hinder margin 

 of each scale on upper half of the body; these spots forming lines along 

 the rows of scales; males nearly uniform; dorsal fin black margined with 

 yellow;- D. 16; A. 15; scales 33-12. multipunctata. 



aa. No black bar at base of caudal. 



c. Body much variegated, D. 14 or 15; A. 13 to 14; scales 34-13; 

 alimentary canal three times total length of the body. vakikcjaia. 



cc. Color uniform with a dark lateral band, which is divided on 

 anterior third of body. D. 16; A. 16; scales 32-1 1. Alimentary canal 

 2 to 2h times total length of body, origin of dorsal midway between 

 base of caudal and nape. bilineata. 



