TRUNCATELLID.E. 137 



rately convex, the last callous, whitish at base, and furnished 

 with a short crest ; aperture perpendicular, broadly oval, angular 

 above, and dilated on the right side ; peristome simple, con- 

 tinuous; right margin slightly expanded; columellar margin 

 adnate. Length 6, breadth 2 mill. 



Truncatella teres, Pfr. in Proc. Z. S. 1856 ; Mon. Auric, p. 188. 



Hah. Isle of Mauritius, and Trinity Bay, Australia. 



10. Truncatella trtjncatula (fig. 1). B.M. 



Shell not rimate, cylindrical, rather solid, scidptured with 

 slightly arched, longitudinal ribs, amber-coloured, fulvous or 

 glassy ; suture median, slightly marginate ; remaining whorls 

 four to four and a half, moderately convex, the last not keeled 

 in front; aperture perpendicular, obliquely ovate; peristome 

 continuous, slightly thickened ; right margin curved above, then 

 slightly arcuate; columellar margin adnate. Length 5-6, 

 breadth 2 mill. 



e 



Animal of Truncatella truncutula. 



a, Side view of animal and shell. 



b, Animal seen beneath as crawling up a glass, taken when the muzzle is 



exserted. 



c, Animal when the foot is extended, in the act of drawing up the shell. 



A. Perfect form : — 



Cyclostoma truncatulum, Drap. Hist. p. 40. pi. 1. f. 28-31. 



Lamarck, Hist. vi. 2. n. 27. p. 149 ; ed. Desh. viii. p. 302. 



Midland, Compl. p. 76. 



Rossm, Ic. vi. p. 53. t. 28. f. 407. 



Potiez et Midland, Gal. Doitai, i. p. 242. n. 22. 

 Cyclostoma subcylimlricum, Fleming, Brit. Arum, p. 258? 

 Cyclostoma concinnum, Scacchi, test*; Philippi. 

 Acmea truncate, Hartm. in SteinmuUer Note Alpina, i. p. 212. 

 Truncatella coslulata, Risso, Hist. iv. p. 125. pi. 4. f. 57. 



Menkc, Syn. ed. 2. p. 43. 



Villa, Disp. Sijst. p. 29. 



