MALACOZOA. TROPIOPODA. LAMELLIBRANCHIATA. 275 



equivalve, very inequilateral ; the posterior side shorter, 

 and angulate. Umbones small, rather pointed, curved 

 a little backwards. Hinge generally with two small 

 divergent teeth in both valves ; lateral teeth elongated 

 and inconspicuous. Ligament external, short, and 

 tumid. Muscular impressions oblong, distant. 



1. Donax Trunculus. Oblong Donax. 



Shell oblong, anteriorly prolonged and rounded, posteriorly 

 sloping rapidly and angulate, moderately convex, smooth, with 

 faint divergent striae ; yellowish-white, with radiating lines or 

 bands, and some concentric markings [of purple or brown ; 

 epidermis thin, pale brown or olivaceous ; inside purple, 

 reddish, or white ; margin striato-crenulate. Length an inch 

 and a-half, height eight-twelfths. 



It varies little in form, but greatly in its colours. 



Along the sandy shores, not uncommon. 



Donax Trunculus. Linn. Syst. Nat. Donax Trunculus. Penn. 

 "Brit Zool. iv. 93. PL 55. f. 45. Donax Trunculus. Turt. Brit. 

 Biv. 123. Donax Trunculus. Mont. Test. Brit. 103. Tellina 

 intus ex viola purpurascens. Lister, Anim. Angl. 190. PI. 5. f. 35. 

 Donax Trunculus. Flem. Brit. Anim. 433. Donax anatinum. 

 Lamk. Syst v. 551 ; Ed. 2. vi. 249. 



2. Donax denticulata. Denticulated Donax. 



Shell crenate, triangular, anteriorly prolonged and semi- 

 oblong, posteriorly truncato-declinate and angulate, moderately 

 convex, thick, glossy, with fine radiating striae, which are 

 punctured or transversely grooved ; a narrow space along the 

 dorsal margin smooth ; two angular ridges from the umbo to 

 the posterior angle, the space between which is striated and 

 punctured, that between the posterior ridge and the margin 

 marked with oblique undulating striae ; the internal surface 

 highly glossed, smooth, the margin crenate ; the central teeth 

 strong, the lateral prominent; the colour white, with purple 

 or violet rays, the inside white. Length nine-twelfths of an 

 inch, height six-twelfths. 



A specimen found in Cruden Bay, by Mr. Alex. Murray, in 

 September, 1842. 



Donax denticulata. Linn. Syst. Nat 1127. Donax denticulata. 

 Turton, Brit. Biv. 124. Donax denticulata. Penn. BritZooLiv. 

 93. Mont. Test, Brit. 104. Donax denticulata. Flem. Brit. Anim. 

 483. Donax denticulata. Lamk. Syst. v. 550 ; Ed. n. vi. 246. 



