268 patellidj:. 



Lottia Antillarum, Sowerbt, Conchol. Manual, fig. 231. 

 Lottia testudinalis, Gould, Inv. 1st ed. 153, fig. 12. 

 Tectura testudinalis, Stimpson, Check Lists, 4. 



Shell oblong-oval, moderately elevated, thin, apex behind the mid- 

 dle, pointed, and turning- forwards ; surface finely checkered with 

 mhmte radiating lines crossed by encirclino- 



Fi" 529 -J a 



,„,^ ■ lines ; general color a greenish white, with 



dark brown stripes radiating from the sum- 

 mit, and frequently dividing, before they reach 

 the margin, which is sharp and entire ; within, 

 the central portion is dark brown, and the 

 margin is more or less bordered or checkered 

 with the same color, by the exterior markings 

 showing through. Ordinary length, four fifths 

 of an inch ; breadth, thirteen twentieths of an 

 inch ; height, one fourth of an inch. 



Found along our whole coast, adhering to the 

 ^ '^ ^. ,. rocks, and is common on the northernmost shores 



T. testudinalis. 



of Europe and America. Gull Island (Smilh). 



Tliis shell varies infinitely in its markings. Tlie general apjjcar- 

 ance is as above described. .Sometimes all exterior coloring is 

 wanting ; and commonly, the lines are so delicate, and arranged in 

 such a manner as to exhibit a kind of n(>twork. The largest speci- 

 mens I have seen were brought from Castine, Maine. These were 

 one and one fourth inches in length. There can no longer be any 

 doubt that this is the shell long known in the north of Europe as 

 P. testudinalis. Specimens sent mo from Ireland, Scotland, and 

 Norway agree in every particular with ours. Probably the P. An- 

 tillarum is the same, though Mr. Sowerby does not intimate this in 

 his correspondence. 



Mr. Couthouy was the first to determine the generic place of this 

 shell, by an inspection of the animal. 



I have employed the generic term Lottia, of Gray, as it has the 

 right of priority, is not an objectionable derivative, and is in general 

 use among all conchologists except the French. PaieUoidea was 

 also given, as the name of a family, by Blainville. The arrange- 

 ment of the branchiae of the animal would, strictly, remove the 

 genus from this family. 



[The name Tectura has precedence. 



