30 Carl L. Hubbs 



PLATE IV 



Figure 6. Distal portion of the gonopodium of AUopoecilia caucana; from a 

 specimen 26 mm. long to caudal fin, from Rio Camarones at Arroyo de Arena, Colom- 

 bia. 



Figure 7. Distal portion of the gonopodium of Mollicnisia latipinna, from a 

 specimen 51 mm. long, from Louisiana. In figures 6 and 7 the membranous hook 

 is labelled m h, the retrorse segment at tip of ray 5, r s.i 



