MALACOZOA. TKOPIOPODA. LAMELLIBRANCHIATA. 233 



7. Anomia strioldta. Striolate Oval Scale-Oyster. 



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

 very convex, somewhat gibbous, concentrically squamoso- 

 nigose 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 from Ano- 

 mia cylindrica, which it most resembles in form. 



First found by me on Sertularise, on the beach near Tarbathie. 



Anomia striolata. Turt. Biv. 233. Anomia striolata. Flem. 

 Brit. Anim. 396. 



SECTION II. DIMYARIA. 



Two adductor muscles leaving two impressions in each valve. 



FAMILY II. MYTILINA. 



Animal obovate or oblong ; with the mantle adhering 

 toward the borders, open beneath, coherent behind, and 

 forming a single orifice 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 linear and dorsal ; the 

 anterior muscular impression very small, the posterior 

 large and roundish. 



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

 silky or hair-like filaments to hard bodies. Some 

 of them afford esteemed articles of food, rather dan- 

 gerous however, as it appears to be in some species 

 poisonous under particular, not yet understood, circum- 

 stances. 



U2 



