HELICIDJE. 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, &e., in woods. 

 i2 



