204 OSTREID^. 



Anomia ephippium. 



Shell rounded, margin irregular ; surface scaly, variously wrinkled and undu- 

 lated; beaks joointed, not quite reaching the margin; ajjerture ovate. 



Ostreum parcum, Lister, Conch, t. 204, fig. 28. 



Anomia ep/ii/ipinm, Lin. Syst. Nat. 1150. — Gmelin, Syst. 3340, No. 3. — Gualt. Tost. 

 t. 97, fig. B. — D'Argenv. Conch, t. 19, fig. C. — Pennant, Brit. Zool. iv. t 62, 

 fif,^ 70. — Chemn. Conch, viii. t. 76, figs. 692, 693. — Montagu, Test. Brit. 153.— 

 Wood, Lhi. Trans, vi. pi. 18, figs. 11,12; Ind. pi. 1 1, fig. 3. — Maton and Rackett, 

 Lin. Trans, viii. 102. — Donovan, Brit. Sh. t. 1, pi. 26. — Born, Mns. fig. 117.— 

 ScHROET. Einl. ill. 383. — Poli, Test. ii. 186, pi. 30, figs. 9, 11. — Da Costa, Brit. 

 Conch. 165, pi. 11, fig. 3. — Favanne, Conch, pi. 41, fig. B. — Dillwyn, Cat. i. 

 286, No. 3. — Blainv. Mai. pi. 59, fig. 3. — Soweruy, Gen. figs. 1, 2, 3. — Turton, 

 Brit. Biv. 227; Concli. Diet. 2. — Lam. An. sans Vert. vii. 273; Encyc. Meth. pi. 

 170, figs. 6, 7. — Gould, Invert. 1st cd. 138. — De Kay, N. Y. Moll. 186, pi. 12, 

 fig. 209. — Flem. Brit. An. 395. 



Shell generally rounded, but often produced at one side or at 

 base, so as to assume an oval form ; its margins more or less jagged, 

 and its surface scaly from the loose edges of 

 the lines of growth, and variously distorted, 

 undulated, and plaited, according to the ob- 

 jects to which it adheres. Lower valve flat, 

 A. ephippium. i^^ aperture ovate, reaching the margin liy a 



fissure. Upper valve slightly convex, little 

 elevated about the beak, which is small, acute, not quite reaching 

 the margin. Substance of the shell pearly, or like talc, of a green- 

 ish tinge, reflecting golden and silvery hues ; within smooth, the 

 muscular impressions opaque white. Usually about an inch in di- 

 ameter, but growing to three times that size. 



It is found in abundance in oyster-beds, adhering to oysters. At 

 New Bedford it has I)eeii found anchored by its muscle to pebbles. 

 Eastport (Cooper} ; wreck of a frigate. Herring Cove (Willis). 



This shell varies so much in its form that it is very difficult to 

 characterize it. The most constant trait is the rugged, scaly ex- 

 terior. It not unfrequently assumes a ribbed appearance, in con- 

 sequence of having adhered to valves of Pecleii irradituis. 



Anomia aculeata. 



Fig. 90. 



Shell rounded, inclined to be straight at the hinge-margin ; color dingy white ; 

 beaks obtuse, terminal; upper valve covered with fine, prickly, radiating lines; 

 lower valve smooth ; aperture circular. 



