112 



Description. — Having no good figure of T. nana, nor specimens to refer to, 

 I can only give the distinctive characters from T. megotaraas pointed 

 out hy Mr. Jeffreys, and also Fischer's description of T. denticulata. 



" Coquille subspherique, mince, tres-onverte anterieurement et posterieur- 

 ment, incgalement divisee en deux portions par un zonule submediane ; bord 

 anterieur etroit, formant un angle droit profond, oreillette anterieure aigue 

 posterieure lisse, plus large, refiechie. Palettes ovalves, allongees, minces ; 

 pedicule grele, court, aigu." — Fischer. 



' ' It differs from megotarain the valves being more compressed and 

 solid, in the anterior auricle being much smaller, and having a more obtuse 

 angle and fewer striae, in the posterior auricle being larger and higher, and 

 especially in the very strong and prominent tubercle or false tooth. The tube 

 of T. n a n a appears to be destitute of calcareous lining, except towards the 

 entrances, while T. megotara forms a solid tunnel ; and the lunule of the 

 pallets is more incised in T. n a n a . Adult specimens measure 21 inches 

 in length. The Turtonian types decidedly belong to this species and not to 

 megotar a." — Jeffreys. 



Turton's miserable description from imperfect and immature specimens, 

 is— 



" Shell with the valves rounded, and without auricles behind, a strong conic 

 tooth on the margin above the teeth. • ' 



T. n a v a 1 i s , Linn. 



T. naval is, Limueus, Syst. Nat. ed. 10, p. 651 ; ed. 12, p. 1267. Adams, 

 Genera, ii. p. 333. Blainville, Diet. Sc. Nat. Hi. p. 267. Bosc, Conch, 

 ii. p. 202, t. 5, f. 4-7. Catlow, Conch. Nomenc. p. 3. Chenu, Encyc. 

 Hist. Nat. Moll. p. 233, f. 245-7. Cuvier, Regne Anim. i. ed. ; ii. p. 494. 

 id. ed. 2, iii. p. 160; id. ed. Griffith, xii. t. 8, f. 2; id. ed. Audouin. 

 t. 114, f. 2. Delle Chiaje, Mem. iv. p. 23, 32, t. 54, f. 2, 8. Deshayes. 

 Traite Elem. i. pt. 2, p. 59, t. 3, f. 1-9. D'Orbigny, Moll.; Sagra's Cuba, 

 p. 211. Eichwald, Fauna Caspio Caucasica, p. 23. Ferrussac, Encyc, 

 Meth. p. 1003. Fischer, Journ. Conch. 2d ser. i. p. 134. Forbes & 

 Hanley, Brit. Moll. i. p. 74, t. 1, f. 7, 8, t. 18. f. 3, 4. Georgi. Beschreib 

 des Russ. Reichs. iii. p. 2216. Gerville, Cat. Coq. Manche. p. 55, 

 Gmelin, Syst. Nat. p. 3747. Gould, Invert. Mass. p. 26. Guerin, 

 Iconog. du Reg. Anim. Moll. t. 33, f. 2. Hanley, Shells of Linn. p. 

 450. Heinrich, Medicinische Zeitung Russlands, 1845, p. 372. Jay, 

 Desc. Cat. 4th edit. p. 9. Karsten, Mus. Leskeanum, t. 1, p. 308. 

 Lamarck, Anim. sans. Vert. v. p. 440. Middendorff, Mai. Rossica, iii. 

 p. 79. Pallas, Reise. Siid. Russ. p. 418. Pallas, Tabl. Phys. de la 

 Tauride, p. 40. Payraudeau, Cog. du Corse, p. 26. Pennant Brit. 

 Zoel. 1 ed. iv. p. 147. Philippi, Moll. Sicil. i. p. 2 ; ii. p. 3. Poli, 

 Test. Utr. Sicil. pt. 2, t. 57, f. 45, 46. Potiez et Michaud, Gallerie des 

 Moll. ii. p. 273. Scacchi, Cat. Coq. Reg. Neap. p. 8. Sowerby, 111. 

 Brit. Shells, t. 1, f. 1. Wheatley, Cat. No. 30. 



T. marina, Sellius, Hist. Nat. Tered. t. 2, f. 2, 3, 6. Jeffreys, Ann. & 

 Mag. Nat. Hist. 3d ser. vi. p. 124. 



T. Batava, Spengler, Skrivt. Nat. ii. pt. 1, p. 103, t. 2, f. C. Gray, 

 Ann. & Mag. Nat. Hist. 2d ser. viii. p. 386. 



T. vulgaris, Lamarck, Syst. des Anim. s. Vert. 1801, p. 128. 



Dentaliurn navis, Linnaeus, Faun. Suec. No. 1329. p. 380. Belkmeer, Natur- 

 kundige. Zee, Worm. t. 2, f. 7, 8, 9. Frisch, Mus. Hoffmannianum, t. 

 1, t. 2, f. 9, t. 3, f. 19, 20, t. 4, f. 2, 5, 6. Massuet, Recherches sur 

 les Vers. t. 1, f. 1, 2. Monath, Dissert, sur le Taret de Hollande, t. 1, 

 t. 2, f. 9, t. 3, f. 19, 20, t. 4, f. 2, 5, 6. Rousset, p. 15, 16, 17, f. 1, 2, 

 3, 4, 10. Vallisnieri, Nat. ii. t. 4. 



