326 TELLINIDiE. 



This genus is closely allied to the last, though there are 

 sufficient distinctions between both shell and animal — dis- 

 tinctions of more consequence than those which separate 

 Psammohia from Tellma. The only British shell included 

 in it has had the felicity of enjoying at various times not 

 fewer than a dozen generic titles. The few known species 

 live in the mud of estuaries, and are gregarious. 



S. piPERATA, Gmelin. 



Plate XV. fig. 5, and (Animal) Plate K. fig. G. 



List. Hist. Conch, pi. 253, f. 88. 

 Mya Hispanica, Chemn. Conch, vol. vi. p. 31, pi. 3, f. 21. 

 Verms Borcalis, Penn. (not Linn.) ed. 4, vol. iv. p. 96, pi. 48, f. 28 (badly). 

 Triyonella plaiia, Da Costa, Brit. Conch, p. 200, pi. 13, f. 1.— Exp. Scient. 



Algerie, Moll. pi. 44 to G4 (shell, animal, and anatomy). 

 Mya Gaditana, Gmei.in, Syst. Nat. p. 3221 (made from figure only). 

 Macira Listeri, Gmelin, Syst. Nat. p. 3261. — Linn. Trans, vol. viii. p. 71. — 

 Dorset Catal. p. 33, pi. 7, f. 1. — Turt. Conch. Diction, p. 83. 

 — Index Testae, pi. 6, Mactra, f. 25. 

 Mactra piperata, Gmelin, Syst. Nat. p. 3261. — Dillw. Recent Shells, vol. i. 



p. 142. 

 Mactra compressa, Pulteney, in Hutchins' Dorset, p. 31. — Mont. Test. 



Brit. p. 96 and 570. 

 Tcllina plana, DoNov. British Shells, vol. ii. pi. 64, f. 1. 



Lutraria compressa, Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 91. — Crouch, 



Introd. Conch, pi. 4, f. 3. — Hanl. Recent Shells, p. 27. — 



Chenu, 111. Conch. Lutraria, pi. 1, f. 7. — Brown, 111. 



Conch. G. B. p. 109, pi. 43, f. 4. 



Lutraria piperata, Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 92. — Philippi, 



Moll. Sicil. vol. i. p. 9. 

 Lislera compressa, Turt. Dithyra Brit. p. 51, pi. 5, f. 1 , 2. — Brit. Marine Conch. 



p. 45. 

 Lutricola compressa, Blainv. Malac. pi. 77, f. 2. 

 Scrohicularia piperata, Philippi, Moll. Sicil. vol. ii. p. 8. 

 Lutraria Listeri, Macgilliv. Moll. Aberd. p. 291. 

 Laviyno calcinella, Recluz, 111. Conch. La\-igno, p. 8. 

 Amphidesma transfer sum, Sav, Americ. Conch, pi. 28, mid. figures (fide Recluz). 



So peculiarly wide a variation of outline seems permitted 

 to this species, that until very lately, the elliptic specimens 

 of the Mediterranean have been sj^ecifically se})arated from 



