MAY, 1902. THE ICHTHVOLOGY OF MEXICO MEEK. 



95 



Girardinichthys innominatum Bleeker. 



Body rather deep, somewhat compressed, the gravid females 

 being particularly deep. Origin of dorsal fin in male midway 

 between base of caudal and middle of opercle, and slightly in 

 advance of origin of anal fin. Anal fin of male modified by hav- 

 ing the first 6 rays about J or f the length of the next rays, and 

 separated from them by a small notch. In this respect they are 

 like Charaeodon, Goodea, etc. Teeth strong, in a band rather than 

 in a single series, the dentition being much the same as that of 

 Fundulus. Peritoneum spotted, not wholly black. Intestinal 

 canal pressed to left side, not coiled, about the length of body; 

 vertebrae 16+21 = 37. Gill-rakers short and stiff, 15 on first gill- 

 arch. 



On fishes less than if inches in length there is a black spot 

 between vent and anal fins. a.nd usually a black spot on belly just 

 at base of pectorals. On some small males these spots rvfn 

 together. Evermann and Goldsborough describe these spots on 

 specimens large and small from Lago de Lerma. The dorsal and 

 caudal fins of males very black: ventrals also black; caudal dusky. 

 Some of the males are almost entirely black. Cross bars are 

 prominent on all the larger specimens; in small specimens these 

 gradually shade out to short lateral blotches,. In general the 

 specimens from Lago de Texcoco are much lighter in color than 

 are those from Lago de Chalco. 



Viviparous; a medium sized female from Chalco, quite 

 plump, 2.24 inches long contained in the ovary 36 fishes. 

 These were well developed, slaty blue, but not speckled, each 

 about .56 inch in length, except one, which, though well developed, 

 was only .40 inch in length. The young were closely crowded 

 together and bent over each other in all sorts of shapes. The 

 egg-yolk still persisted as a slender string attached to the abdo- 

 men. A female from Texcoco, 2.19 inches long, contained 52 

 embryos, each .55 inches in length. A large female from the 

 same place, 2.69 inches long, contained 240 (white and slender) 

 young. Male fish somewhat smaller than females. 



The viviparity of this species was noticed in a recent paper 

 by Evermann and Goldsborough. The peculiar modification of the 

 anal of the male was overlooked, or all of their specimens were 

 females. Viviparity is no doubt much more common in species 

 of this family than was formerly supposed. Chalco: Texcoco: 

 Xochomilcho. 



