EXPLANATION OF PLATE 44 



All figures approximately natural size 



Fig. 1. Ostrea titan Conrad. This species is sometimes gigantic in propor- 

 ons, being as much as 18 inches high, with the shell several inches thick. 



Fig. 2. Solen perrini, n. sp. Longitude, 76 mm. 



Fig. 3. Siliqua lucida Conrad. Longitude, 18 mm. 



[518] 



