SAXICAVA. 141 



1. S. ARCTicA, Linnscus. 



Anterior extremity attenuated and cuneiform, witli a lunule- 

 like excavation in front of the prominent beaks ; posterior extre- 

 mity always the broader; ligamental edge almost always incurved ; 

 linear ridges spinous except in very aged individuals ; hinge 

 toothed. 



Plate VI. figures 4, 5, 6. 



Mya arctica, Linn. Syst. Nat. p. 1113. — 0. Fabr. Fauna Grsenl. p. 407. — 



TuRT. Conch. Diction, p. 104. — Wood, General Conch, p. 95. 

 Solen mimitus, Linn. Syst. Nat. p. 1114. — Mont. Test. Brit. p. 53, pi. 1, f. 4. — 

 Spengl. Skrivt. Naturh. Selskab. vol. iii. part 2, p. 1 13. — Linn. 

 Trans, vol. viii. p. 47- — Turt. Conch. Diction, p. 161. — Chemn. 

 Conch> Cab. vol. vi. p. 67, pi. 6, f. 51, 52. — Wood, General 

 Conch, p. 139, pi. 34, f. 5, 6. — Dillw. Recent Shells, vol. i. p. 

 69. — Lam. Anim. s. Vert. ed. 2, vol. vi. p. 57. — Index Testa- 

 ceol. pi. 3, f. 33. 

 Donax rhomhoides, Poli, Test. Sicil. pi. 15, f. 12, 15. 

 iW^i«7Msp*«mMS, Mont. Test. Brit. p. 165. — Linn. Trans, vol. viii. p. 112. — 



Dillw. Recent Shells, p. 305, 

 Hiatella arctica. Lam. Anim. s. Vert. ed. 2, vol. vi. p. 443. — Flem. Brit. Anim. 

 p. 461. — Brit. Marine Conch, p. 59. — Bowdich, Conchologj% 

 Biv. f. 40. — Crouch, Introd. Conch, pi. 8, f. 6. — Hanl. 

 Recent Shells, p. 150. — Cuvier, R. Anim. (ed. Croch.) pi. 

 110, f. 1. 

 Anatina Arctica, Turt. Dithyra Brit. p. 49, pi. 4, f. 7, 8.— Brit. Mar. Conch, p. 42. 

 Affina purpurea, Turt. Dithyra Brit. p. 54, pi. 4, f. 9. — Brit. Marine Conch. p. 60. 

 Solen purpiirous, Flem. Brit. Anim. p. 459. 

 Saxicava rhomhoides, Desh. in Lam. ed. 2, vol. vi. p. 153. 



Saxicava arctica, D'ESn. Elem. Conch, pi. 12, f. 8, 9. — Phil. Moll. Sicil. vol. i. p. 

 20, pi. 3, f. 3, and vol. ii. p. 19.— Macgill. Moll. Aber. p. 

 285. — LovEN, Ind. Moll. Suecise, p. 40. 

 Hiatella minuta, Turt. Dithyra Brit. p. 24, pi, 2, f. 12. — Brown, 111. Conch. G. 



B, p, 103, pi, 47, f. I, 16. 

 Saxicava purpurea. Brown, III, Conch, G, B. pi, 42, f, 30, 31. 

 Saxicava rubra, Desh. Exp. Algerie, Moll. pi. 66, f. 18, 19 (shell and animal). 

 Hiatellc, Chenu, Traite Element, p. 58, f. 206. 



Nothing but the most searching scrutiny will distinguish 

 this closely allied Saxicava from its congener rugosa, the 

 young of which is often confused in cabinets with that of 



