LEUCONIA. 155 
Jamipia bidentata Leach Cat. (Conf. Zeitschr. f. Malak. 1849. p. 57.) 
-— -- Bromn ll Conch. Gr. Br. p. 22. t. 8. f. T. 
Auricula bidentata. Fér. Prodr. p. 103. n. 9. 
-— — Gray Aun. of Philos. XV. 
— -— Jeffr. in Linn. Trans. XVI. p. 368. 
Conovulus bidentatus (.Leuconia) Gray in Turt. Man. p. 227. t. 12. 
f. 145. *) 
— — Clark in Ann. and Mag. 2d. ser. VI. p. 445. 
— — Forb. et Hanl. Brit. Moll. IV. p. 191. t. 125. 
E172. 
— bidens Gray in "Turt. Man, Ind. t. 12. 
Acleon bidentatus Flem. Brit, Anim, p. 337. 
Leuconia bidentata Gray in Proc. Zool. Soc. 1847. p. 179. 
- — Pfr. Syn. Auric. n. 165. 
— — H. et 4. Adams Gen. rec. Moll. II. p. 245, 
8. Spira erosa: 
Auricula erosa Jeffr. in Linn. Trans. XVI. p. 369. 
y. Gracilior, spira productiore, apertura angustiore, pliea columellari saepe 
fere obsoleta: 
Voluta Boys et Walker 'Test. var. p. 17. t. 3. f£. 61? **) An potius Cy- 
lichna. obtusa? 
— alba Mont. 'Test. Brit. p. 245? ***) 
— —  Dillm. Descr. Catal. I.-p. 508. n. 22. 
— —  Turt. Conch. Dict. p. 250. 
Auricula alba Fer. Prodr. p. 103. n. 10. 
— — Gray Ann, of Philos. XV. 
— —  Jeffr. in Linn. Trans. XVI. p. 36$. 
— — Forbes Malac. Mon. p. 12. 
Volvaria alba. Fleming Brit. Anim. 
Conovulus albus (Leuconia) Gray in Turt, Man. ed. nov. p. 227. t. 12. 
f. 146, 1) 
-— bidentatus var. Forb. et Hanl. Brit. Moll. IV. p. 192. 
Leuconia. alba H. et 4, Adams in Proc. Zool. Soc, 1854, p. 36. n. I. 
Gen. rec. Moll. II. p. 248. t. 83. f. 3. 
— —  Pfr. Syn. Auric, n. 166. 
Habitat in littore Britanniae. 

*) Shell ovate, ventrieose, smooth, shining white; spire short; suture 
indistinct; mouth oblong; two of the plaits on the pillar larger than the 
rest; peristome slightly thickened and reflexed in front. (Gray l. e.) 
**) Voluta alba opaca, longitudinaliter striata, — "This shell resembles 
Mr. Pennant's voluta jonensis, but differs in the form of the aperture, as 
well as in the size. (Boys et Walk. l. c.) 
979*) V. with. an oval, white shell, with four volutions, finely striated: 
aperture long, narrow. Length one tenth of an inch. (Mont. l. c.) 
t) Shell fusiform, pointed, thin, white, pellucid, slightly transversely 
striated; whorls six; mouth slender, oblong; pillar two-plaited. (Gray l. c.) 
