PLATE XX. 



Willemcesia leptodactyla (p. 163). 



Fig. 1. Pereion, with lateral wall of the carapace removed to show the position and 

 arrangement of the branchiaa, 



C. Metope or facial region, showing on one side the relative positions of 



the ophthalmopod (a), and first (b) and second antenna? (c), from 

 within. 



d, d. Siagones or mandibles (the synaphipod should have only two joints). 



d", d". Metastomata. 



ma. Cheiloglossa, as seen between the mandibles. 



?//. Third pair of pereiopoda with mastigobranchial lash and podo- 

 branchial plume. 



in'" . One of the hairs and spines from the mastigobranchia ; enlarged. 



m". Section of a podobranchial plume. 



,, 2. Ovum enlarged, showing advanced condition of the embryo. 



