TAPES. 379 



T, DEcussATA, Liiinceus. 



Suboval, subrhombic, coarsely decussated by concentric sulci 

 and radiating striae, verrucose in radiating rows at the posterior 

 extremity : front dorsal edge moderately long ; umbones rather 

 prominent : pallial sinus not peculiarly large. 



Plate XXV. fig. 1. 



Lister, Hist. Conch, pi. 423, f. 271. 

 Venus dcoussaia, hmN. Syst. Nat. p. 1135 — Pultenev. Hutchins, Dorset, p. 



34 (chiefly).— DoNOV. British Shells, vol. ii. pi. 67.— Mont. 



Test. Brit. p. 124 Linn. Trans, vol. viii. p. 88, pi. 2, f. 6. 



—Dorset Catalogue, p. 36, pi. 6, f. 4, (not well).— Turt. 



Conch. Diction, p. 244.— Turt. Dithyra Brit. p. 158, pi. 8, 



f. 10. — Brit. Marine Conch, p. 93. — Chemnitz, Conch. Cab. 



vol. vii. p. 58, pi. 43, f. 455, 456.— Dillw. Recent Shells, 



vol. i, p. 206.— Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 



357 (not var. 4.)— Index Testaceolog. pi. viii. f. 107.— Phi- 



LiPPi, Moll. Sicil. vol. i. p. 45, pi. 4, f. 11, and vol. ii. p. 35. 



— Hanl. Recent Shells, p. 122, vol. i. pi. 8. f. 107. 

 Venus Utterata (not of Linn.) Penn. Brit. Zool. ed. 4, vol. iv. p. 9<i, pi. 57, f. 53. 

 Cuneus reticulatus. Da Costa, Brit. Conch, p. 203 (in part), pi. 14, f. 4 (badly). 

 Venus florida, Poli, Test. Sicil. pi. 21, f. 16, 17- 

 Venerupis decussata, Flem, Brit. Anim. p. 451. — Macgilliv. Moll. Aberd. p. 



339. 

 Pullastm decussata, Brown, 111. Conch. G. B. p. 88, pi. 37, f. 5, 6. 



The shape of V. decussata, whose valves are destitute of 

 lustre, opaque, solid, ventricose, and extremely variable in 

 painting, is suboval and subrhomboidal ; its convexity is 

 most apparent around the umbonal region, the sides being 

 comparatively flattened. As respects colouring, our British 

 specimens do not quite display so brilliant a diversity of 

 painting as the continental ones, but exhibit various shades 

 of buff, drab, or rufous, rayed, freckled, or zig-zagged 

 Avith markings of a deeper tint, with generally more or 

 less of a livid tinge ; occasionally, they are of an uniform 

 reddish cast, but we have rarely met with any of that 

 chalky whiteness which is so common in pullasira. The 



