Labyrinthici and Holconoti 



379 



four times larger than the young of a Pomotis (of the same 

 size) a full year old. In this respect these fishes differ from all 

 the other viviparous species known to us. There is another 

 feature about them of considerable interest, that while the two 



FIG. 312. Viviparous Perch (male), Hysterocarpus traski Gibbons. Battle Creek, 

 Sacramento River. (Photograph by Cloudsley Rutter.) 



adults differ markedly in coloration, the young have the same 

 dress, light yellowish olive with deeper and brighter transverse 

 bands, something like the young trout and salmon in their parr 

 dress." 



