\<>0 WORMS. TESTACEA. 43. 44. 



triangular shape than V. verrucosa and not slightly truncate on the 

 anterior part, whitish, with 15 or x6 obtu»e very regular but not 

 membranaceous wrinkles. 



£10. V. triangularis. Somewhat triangular, equally slop- 

 ing each side under the beak, yellowish-white, with a 

 few antiquated ridges: in one valve 2 teeth, and a 

 lateral semilunar lamina; in the other 3, 2 of them 

 diverging. 



Montague Bri. Shell, app. p. 577. tab. 17./. 1. 



Shell half an inch long, nearly as broad ;. smopth Within : beak 

 cental, very prominent, a little oblique* with a lanceolate de- 

 prefsion under it : one' valve with 2 strong teeth, one cloven, the 

 other triangular with a semilunar lamina near it ; the other valve 

 with 3 teeth. 



280. Y.spinifera. Suboval, subtriangular,. with fine equi- 

 distant raised ridges becoming confluent in pairs at 

 the anterior side and forming obtuse reflected spines. 



Montague Brit. Shells, app. p. .577. 



Shell half an inch long, rather, more broad, yellowish-white, with 

 numerous parallel somewhat reflected ridges ending on the margin 

 . of the cartilage slope in short spines, within white smooth': beak 

 nearly central, a little turned, with a lanceolate deprefsion beneath 

 it : hinge with a single tooth and a small cavity and a remote late- 

 ral lamina in one valve; in "the other valve 2 teeth, 



43. CHAMA. 



281. Ch. Cor, Subglobular, heart-shaped, slightly stri- 

 ate, gaping at the anterior slope : beak much 

 incurved. ,j 



Donovan tab. 134. lister conch, t. 275./. 111. 



Shell near 3 inches wide,, strong, thick, covered with a yellow- 

 brown.skin under which it' is varied wHthhroWn and white, slightly 

 wrinkled transversely, with the margin entire: beak reddish, 

 * ; large, prominent, twisted inwards: hinge strong, \vith flattish 



teeth.' 



44. ARCA. Jrk-tisIL , ; > , ,, ;" .'.' .. 

 %%% Apilosa. Suborbicular, ^xacUy equilateral, faintTy 

 striate longitudinally witti transverse wrinkles^ co- 

 vered with a villous skin under which it is marked 

 with zigzag brown lines. 



Br. Zool. ti 58./. 58. Donov. t. 37. A. Glycymeris. 



Shell 2 inches and- a half- wide, covered with a dark-brown hairy 

 skin, beneath -which are chesnut or orange angular stripes ; within 

 white with a crenate margin ; beah prominent, central, straight. 



283. A. Glycymeris. Suborbicuiar, a little irregular, 

 faintly 'striate, Covered 1 with a villous skin, under 

 which it is marked with yellowish spots or bands. 



linn. Trans. v.iii. j>. 95. tab.^.f. 3. 



.Shell resembling the last, but is more gibbous, and not quite 

 equilateral, within white with a crenulate margin : teeth about 10, 

 transverse. , , . , 



284. A. lactea. Rhombic, yellowish-white, covered with 

 a brown hairy skin, closely and . regularly striate 

 longitudinally with a few concentric ridges. 



Donovan t. 135. Br. Zool. t. 58./. 59. 



Shell an inch and a half long, 3 quarters of an inch broad, some- 

 times reticulate, sometimes rounded at both ends, sometimes a 



