PLATE XL VII. 



FIG. 



1. SERTULARELLA TRICUSPIDATA, p. 239, nat. size. 



1 a. The same, enlarged. After Alder. 



2. SERTULARELLA RUGOSA, p. 241, nat. size. 



2 a. The same, magnified. 2 b. A portion, more highly 



magnified. From drawings by Mr. Tuffeu West. 



3. SERTULARELLA TENELLA, p. 242, nat. size. 



3 a. The same, magnified. 3 b. A single calycle, more 



highly magnified. 3 c. The gonotheca. After Alder. 



4. SERTULARELLA FUSIFORMIS, p. 243, nat. size. 



4. A portion, magnified. 46. The gouotheca. From 

 drawings by the Author. 



