HELICIDvE. 191 



racters so nearly allied. The only British species forms 

 a very distinct section, perhaps genus, from the 

 larger exotic kinds. 



a. ACICULA Nilson. 



The shell turreted, polished, transparent ; mouth ob- 

 long, rather narrow ; upper tentacles subulate, blunt, 

 eyeless. 



64. 1. ACHATINA. Acicula. Needle Agate Shell, 

 (t. 6. f. 77.) Shell slender, smooth, polished, 

 white, with sixflat volutions ; the lower one as 

 long as all the others ; mouth elliptical. 



Achatina Acicula. Lam. vi. p. 133. 



Bulimus Acicula. Brug. E. M. 22. ; Drap. p. 75. 

 t. 4. f. 25, 26. ; Brard, p. 100. t. 3. f. 21. 



Buccinum terrestre. Mont. p. 248. t. 8. f. 3. 



Acicula. Miiller, Verm. ii. 150.; Dill- 



wt/n, p. 652. 



Helix octona. Gmel. S. N. i. 3653. 



Cionella Acicula. Jeffreys, Linn. Trans, xvi. 348. 



Among the roots of trees, at the base of limestone 

 rocks. 



Animal pellucid white, granulately striated ; tenta- 

 cula retractile, cylindrical, upper pair longest, granu- 

 lar, not thickened at the top, smooth, convexly 

 truncated, without any black spot (eyes) ; lower pair 

 opposite the angles of the mouth ; foot compressed, 

 pointed behind ; breathing-hole large, rounded, in the 

 middle of the outer lip of the shell. 



Shell not a quarter of an inch long, taper ; aper- 

 ture oval-oblong, appearing as if cut off at the base, 

 giving the end of the pillar the resemblance of a 



