1899.] NATURAL SCIENCES OF PHILADELPHIA. 523 



Pacific, though on the shores of California it is very abundant. 

 Many of the less-known species which I found have evidently a 

 wide distribution. Thus Trippa areolata had previously been 

 reported from the coast of Madras, Dolahella Hasseltii from Java 

 and Mauritius, and Aplysia nigrocincta from the latter locahty. 

 Though the coast of Samoa is exceedingly rich in marine life, I 

 observe that many species are smaller than those described from 

 other places. 



Cyerce nigra, Aplysia Benedicti and Elysia Hendersoni were 

 found in small flocks or families of from ten to fifteen individ- 

 uals ; Dolabella and the Dorididce mostly in pairs. 



EXPLANATION OF PLATE XIX. 



la. Doridium Pilsbryi, n. sp., dorsal aspect. 



lb. Doridium Pilsbryi, u. sp., ventral aspect. 



2a. Aplysia Benedicti, n. sp. 



2b. Aplysia Benedicti, n. sp., central and lateral teeth. 



3. Dolabella Hasselti Fer. 



4. Elysia Hendersoni, n. sp. 



