88 THE NAUTILUS. 



Mayer (Sea-Shore Life, N. Y. Aquarium, Nature Ser. No. 1^ 

 1905) ; Julia E. Rogers (The Shell Book 1908) ; Josiah Keep 

 (West Coast Shells 1911). Professor Keep gave a somewhat 

 popular name to every shell ; but I cannot agree with him in 

 some cases. Why Polinices (not Polynices) should be called 

 "moon shell " while Natica is made a part of a common name 

 of one species, I cannot see. This name is also used in the Shell 

 Book where the inconsistency in the use of common names 

 greatly mars the value of the work in this respect. 



There is one thing we should take into consideration, and that 

 is, there are English names in general use, which may be found 

 in the various dictionaries. Turning to the Century Dictionary 

 under sea-snail, we find the following : — In conch, a marine 

 gastropod whose shell resembles a helix, as those of the family 

 Littorinidae, Naticidae and Neritidae. Periwinkle is generally 

 applied to the former, and as the latter has a restricted distri- 

 bution and is confined to the more tropical waters, it seems 

 therefore that the term sea-snail would be more appropriately 

 restricted to the Naticidae. Dr. Mayer gives a pertinent name 

 which combines their nest or " sand-collar" with the shell ; for 

 Polinices heros (Natica or Lunaiia heros of authors) the Northern 

 Sand-collar Snail, and for P. duplicata the Southern Sand-collar 

 Snail. Local or provincial names that are misleading should 

 not be considered in adapting fixed common names, for ex- 

 ample, among the New England fishermen the name *' cockles " 

 is applied to the sea-snails (Polinices), but in all dictionaries 

 the name cockle usually applies to the various species of Cardiimi. 



The name Periwinkle is almost universally used for the 

 species of lAtorina, (generally written Littorina the original spell- 

 ing of the genus being Litorina) although Keep uses the term 

 ^^ Littorine.''^ The name "Common Periwinkle " should be 

 applied to the original and widely distributed species L. littorea 

 and not to L. irrorata as in the Shell Book ; to the latter, the 

 name Dotted Periwinkle might be applied. The name Red 

 Periwinkle seems better than "Rough Winkle," for L. rudis, 

 for the shell, although usually more or less reddish, varies 

 from a grayish white to a dark brown (var. tenebrosa). The 

 Seaweed Periwinkle for L. obtusata palUata suggested by Dr. 



