MALACOZOA. TEOPIOPODA. LAMELLIBRANCHIATA. 233 



7. Anomia strioldta. Striolate Oval Scale-Oyster. 



Shell subovate, thin, subpellucid, white; the upper valve 

 ven- convex, somewhat gibbous, concentrically squamoso- 

 nig'ose toward the crenulate margin, with radiating striae, the 

 ridges between which are scaly or somewhat spinous ; the 

 umbo convex, glossy, narrowed to an obtuse curved point pro- 

 jecting a little beyond the lower valve ; which is flat, irregu- 

 larly lamellate, with the aperture small, roundish, and com- 

 municating with the margin by a narrow slit. Length about 

 a fourth of an inch, breadth a third less. 



It appears to me that this species is truly distinct fi-om Ano- 

 mia cylindrica, which it most resembles in foi-m. 



Fkst fomid by me on Sertularite, on the beach near Tarbathie. 



Anemia striolata. Turt Biv. 233. — Anomia striolata, Flem. 

 Brit. Anim. 396. 



SECTION 1 1. — D I M Y A R T A. 



Two adductor muscles — leaving two impressions in each valve. 



Family II. — ^Mytilixa. 



Animal obovate or oblong ; with the mantle adhering 

 toward the borders, open beneath, coherent behind, and 

 forming a single orihce for the anus ; a slender lingui- 

 form foot, furnished with a byssus at its base behind, 

 and two pairs of retractor muscles ; two adductor mus- 

 cles, the anterior very small ; branchiae moderate, pec- 

 tinate ; mouth moderate. 



Shell regular, equivalve, very inequilateral, calcareous 

 and covered with an epidermis, or horny and bare ; with 

 the hinge toothless; the ligament hnear and dorsal; the 

 anterior muscular impression very small, the posterior 

 large and roundish. 



Marine animals, fixed by means of a byssus or tuft of 

 silky or hair-like filaments to hard bodies. Some 

 of them afi'ord esteemed articles of food, rather dan- 

 gerous however, as it appears to be in some species 

 poisonous under particular, not yet understood, circum- 

 stances. 



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