TECTURA. 267 



Fundy. It is that referred to as D. entale by Dr. Mighcls. Having 

 had the opportunity of comparing nu- ^..^ ^gg. 



merous specimens of the European spe- 

 cies with ours, I am convinced they are 

 distinct. It differs from D. Taretiti- 



num in being larger, tapering more gradually to a point, in being 

 more rugose with the lines of growth and in being almost always 

 destitute of longitudinal stria?. 



The length of one specimen is an inch and one half ; the diameter 

 at the aperture, one hundred and seventy-five thousandths of an 

 inch. Imperfect specimens indicate a length of two inches. {Siimp- 

 sun.) 



Family PATELLIDyE, D'Oeb. 



Shell depressed, conical or cap-shaped ; aperture wide, with a 

 crescentic, muscular impression, interrupted in the region of the 

 head. 



Ociiiis TECTURA, Aud. and Milne-Ed. 1830. 



Shell basin-shaped, apex obtuse, usually more depressed and 

 thinner than Patella, and distinguished from it chiefly by its in- 

 habitant. 



Tectura testudinalis. 



Fig. 12. 



Shell oblong-oval, greenish white, for the most part with brownish sub-divid- 

 ing radiations ; centre witliin, dark brown. 



Patella testudinalis, Muller, Prodr. p. 237. — Fabr. Fauna Gnpiil. 385. — Lam. An. 



sans Vert. vii. 543. — Dillwyn, Catai. 1045. — Wood, Catal. No. 6.3, pi. 37. 

 Patella testiidinaria, Kae.meker, Kiidolst. Conch. 12, pi. 2, fig-s. 4, 5. 

 Patella tfstatlinaria droenlandica, Chemv. Conch, x. 325, pi. 168, figs. 1614, 1615. 

 Patella tessellatn, Muller, Zool. Dan. Prodr. iii. 2868 ; Z. D. t. 12, fii^s. 6-8. 

 Patella Clealandi, So^VERBY, Records of Lin. See. viii. 621. — Fleming, Brit. Anim. 



287. 

 Patella virr/inea, Muller, Prodr. iii. 2867; Zool. Dan. t. 12, figs. 4, 5, 

 Patella virr/inea ? Gmelin, 3711. — Dillwyx, Catal. 1052. 



Patella amcena. Say, Journ. Acad. Nat. Sc. ii. 223 (June, 1822) ; ed. Binney, 73. 

 Patelloidea anirena, Couthouy, Bost. Journ. Nat. Hist. ii. 171. 

 Patelloida t'^stadinnlis, Lea, Trans. Anier. Phil. Soe. (New Series), vii. 73. — De Kay, 



N. Y. Moll. 162, pi. 9, fiir. 196. 

 Pattlla clypeus, Brown, Conch, of Great Brit. &c. pi. 37, figs. 9, 10. 



