158 
HELICIDJE. 
This shell varies in shape^ size^ and colour, being 
sometimes transparent greenish white, ^.from want of 
substance and colouring matter. It also varies in 
having one or two additional small teeth in the peri- 
stome alternately with the larger ones. 
9. Achatina Lam. (Agate Shell.) 
Animal like Bulimus^ with four tentacles and an 
oval-oblong or somewhat cylindrical shell, ob- 
tuse at the tip ; aperture longitudinal, oval ; the 
outer lip thin, without any internal rib, and 
never reflected ; pillar smooth, simple, truncate 
in front. 
The abruptly truncated termination of the pillar 
or inner lip of the shell will immediately distinguish 
this genus from Bulimus^ to which it is in other cha- 
racters so nearly allied. The only British species 
forms a very distinct section, perhaps genus, from 
the larger exotic kinds. 
a. Shell turreted^ polished, transparent i mouth oblong, 
rather narrow; upper tentacles subulate, blunt, 
eyeless. (Styloides. Acicula Nilson.') 
69. 1. Achatina Acicula. Needle Agate Shell. — 
Shell slender, smooth, polished, white, with six 
flat volutions ; the lower one as long as all the 
others; mouth ellipticah (t. 6. f. 77.) 
Achatina Acicula. Lam. vi. p. 133. ; Rossm. Icon. x. f. 658. ; 
Forbes and Hanley.^ JB. M. iv. 130. t. 128. f. 4. — Bulimus 
Acicula. Brug. E. M. 1. 311.; Drap. p. 75. t. 4. f. 25, 26.; 
Brardy p. 100. t. 3. f. 21. — Buccinum terrestre. Mont. T. B. 
p. 248. t. 8. f. 3. — Buccinum Acicula. Muller.^ Verm. ii. 
