PLATE II. 



A M. stands for adductor muscle. 



Jul. stands for intesl ln< 



Fig. 1. Cypris-larva of Upas mistrnlis. Darwin, .sagittal section ; magnified 70 diameters 



Fig. 2. Same larva in a slightly older stage, longitudinal section ; magnified 70 diameters. 



Fig. 3. Cypris-larva of Scalpellv/m regium (Wyv. Thorns.), Hoek, which is destined to 

 develop into a male; magnified !»4 diameters. 



Fig. 4. Cypris-larva of Scalpellum t riangulare, Hook, which is also destined to become 

 a male; magnified 94 diameters. 



Fig. 5. Group of cement-cells with their duets and pale yolk-elements of the Cypris- 

 larva of Lepas australis, Darwin ; magnified 275 diameters. 



