HELIX. 141 



pyramidal, with very numerous regular longitudinal 

 lamellae not shooting in the middle into spinous pro- 

 jections ; spire composed of six rounded and deeply 

 divided volutions, which very gradually decrease from 

 the tumid and rounded base ; the tip obtuse and 

 usually of a whitish colour ; aperture narrow crescent- 

 shaped, wider than long, the margin thin and reflected 

 over the umbilicus, which is small and deep. 



Like that of H. aculeata, the periostracum of this 

 species rises into thin laminar foliations, which in 

 various positions of light reflect a velvety or satin- 

 like lustre ; but the foliations are infinitely more 

 numerous and compact, not shooting into spinous 

 processes in the middle ; the shape of the spire is 

 also very different, not decreasing in a conical 

 manner, but regularly pyramidal ; and the aperture, 

 instead of projecting forward in a semielliptic form, 

 is narrow crescent-shaped, without the internal rib 

 round the margin. 



i. Shell depressed, more or less keeled, brown or varied, 

 striated ; whorl closely applied ; peristome simple, 

 slightly depressed; jaws slender, striated and 

 crenulated. (Delomphalus Ferus.) 



59. 26. HELIX rotundata. Radiated Snail. Shell 

 flattish, slightly carinate, deeply striate, rufous- 

 grey with chestnut spots, (t. 5. f. 44.) 



Helix (Delomphalus) rotundata. Charpent, 1837. Helix ra- 

 diata. Da Costa, p. 57. t. 4. f. 15, 16. ; Montagu, p. 431. 

 t.24. f. 3.; Turton, Man ed. 1. 59. f. 44. Helix rotundata. 

 Muller, 29. ; Drop. p. 114. t. 8. f. 57. ; Brard, p. 51. t. 2. 

 f. 10, 11. ; Jeffreys, L. T. xiii. 342. ; Rossm. Icon. vii. f.454.; 

 Forbes and Hanley, B. M. iv. 80. t. 119. f. 6, 7. t. G G G. 



