HELICID^E. 171 



very deep; aperture oblong crescent-shaped, com- 

 pressed, oblique, as long as it is wide. 



Mr. Alder observes, that continental specimens of 

 this shell are larger and rather more open in the umbi- 

 licus than British ones ; which induced M. de Ferussac 

 to think that they might be distinct. The same re- 

 mark is applicable to Helix nitidula, but in both cases 

 he thinks it amounts to nothing more than a variety, 

 H. nitens Fer. Tab. Moll, is only the English variety 

 of the species in a small state. 



H. nitens of Michaud, if we may judge from the 

 figures, is H. nitidula Drap. Mr. Alder suspects Mi- 

 chaud's H. nitidula is, like that of Pfeiffer, the H. 

 nitidula var. /3 of Drap., which is his H. radiatula. 



Dr. Turton, in the first edition of this work, mis- 

 placed the numbers of these shells : they ought to have 

 been reversed ; fig. 38. is Z. lucidus and 40. Z. cellarius. 



50.7. Zonites purus. Delicate Snail, (t. 4. f. 43.) 

 Shell depressed, rather shining, transparent 

 white, slightly striated or wrinkled, with four 

 shining whorls set diagonally ; under side more 

 flattish than the upper, and without any appear- 

 ance of opacity ; umbilicus rather large. 



Helix pura. Alder, Cat 12. n. 46.; Mag. Zool $ 

 Bot. ii. 108.; Turton, Man. ed. 1. 59. (not the 

 figure). 



Helix nitidula var. ft. Jeffreys, Linn. Trans, xiii. 

 511. 



Helix Alderi. Bean, MSS. ; Brit. Mus. 



Var. Shell pale horn-colour ; animal rather darker. 

 Alder, Cat. Mag. Zool. $ Bot. ii. 108. 



Helix nitidosa. Fer. Tab. Moll, (not synonyma). 



Inhab. under stones, decayed leaves, &c, in woods. 

 i 2 



