Plate IV. 
Fig. 1. Echnirus vulgaris, Sav. About natural size. 
Fig. 2. Priapulus caudatus, Lam. The specimen is somewhat contracted, 
so as to give prominence to the transverse rugae. 
Fig. 3. A very large specimen, apparently of Amphiporus pulcher. En¬ 
larged. 
Fig. 4. Sgnapta inhcerens, 0. F. Muller. Somewhat enlarged. 
Fig. 5. Cucumaria lactea, Forbes & Goodsir, attached to a glass vessel. 
Enlarged. 
