346 TEUEBRATULID.E. 



natural internal surface of the shell is examined, a very 

 beautiful appearance is presented by it; a most regular 

 imbricated arrangement is seen, exactly resembling a tiled 

 roof, in which the lower margins of the tiles are rounded, 

 instead of being quadrangular. If a portion of the surface 

 be slightly rubbed down, so that the connection of their 

 tile-like markings with the interior structure can be traced, 

 it is seen that they are the extremities of the longitudinal 

 folds just mentioned, each row of them belonging to one 

 lamina, and a series of the laminae cropping out, one 

 beneath another." 



H. psittacea, Chemnitz. 

 Surface blackish, not punctulate, with radiating strire. 



Plate L VI I. fig. 1, 2, 3. 



Davila, Catal. Cabinet, vol. i. pi. 20, f. b. B. 

 Anomia rostrum-psittaci, Chemn. Conch. Call. vol. viii. p. 10(5, pi. 78, f. 713. 

 „ psittacea, Gmelin, Syst. Naturae, p. 3348. — Turt. Conch. Diction, p. 5, 

 f. 42, 43, 44.— Dillw. Recent Shells, vol. i. p. 296.— Index 

 Testaceolog. pi. 11, f. 27— Mawe, Linn. Conch, pi. 1.5, f. 3. 

 Terebratula psittacea, Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 333. — Turt. 

 Dithyra Brit. p. 236.— Fleming, Brit. Animals, p. 368. 

 — Thompson, Ann. Nat. Hist. vol. xiii. p. 433 — Brit. 

 Marine Conch, p. 127.— Brown, Illust. Conch. G. B. 

 p. 68, pi. 46, f. 2, 3, 4.— Alder, Cat. Moll. Northum- 

 berl. and Durh. p. 74. — Crouch, Introd. Lain. Conch, 

 pi. 13, f. 4. — Sowerbv, Genera Shells, Terebratula, f. 

 5 ; Thesaur. Conch, vol. i. p. 342, pi. 71 , f. 78, 79, 80.— 

 Sowbrby (Junior), Conch. Manual, f. 202. — Gould, In- 

 vert. Massach. p. 142, f. .01.— Reeve, Conch. Systemat. 

 pi. 126, f. 5. 

 Hypotliyris psittacea, King, Ann. Nat. Hist. vol. xviii. p. 238. 



This quaint and sombre-looking species, one of the very 

 scarcest of our native shells, is of a somewhat globosely 

 triangular shape, being acuminated above, and rather 

 abruptly dilated below : it is very thin, gibbous, not 



