inhabits the Helix nemoralis, L. of Europe, according to 

 Kirby and Spence. 



REFERENCE TO THE PLATE. 



The two upper figures represent profile and basal views of the shell. 



HELIX THYROIDUS. 



DESCRIPTION. 



Shell rather thin, convex, umbilicate, pale reddish brown, 

 immaculate : volutions five, 's^Tinkled : mture distinct, but 

 not very deeply impressed : labrum abruptly contracting 

 the aperture, rather widely reflected, flattened in the plane 

 of the mouth, excepting the superior third, and white : 

 umbilicus narrow, distinct : labium with an oblique w hite 

 tooth, rather above the middle and not very prominent 



SYNONYMS. 



Helix thyroidus. Nobis. Journ. Acad. Nat. Sc. voL 



i. p. 123. Nicholson's Encycl. (Jim. edition J — Ferus- 



sac, Tabl. System, p. 33. 

 Cochlea umbilicata, capillaceis stryis per obliquum do- 



nata, Unico dente ad fundum oris. Lister Synopsis 



Conch, pi. 91, f. 91. 



The following synonyms are from Ferussac Tab. Syst. 

 Petiver, Gazophyll. t. 405, f. 4. Philos. Trans, vol. xx, 



p. 375 ; Cochlea terrestris virginiana &c., Schro- 



ier, Enleit. ii. p. 1 92, No. 60. 



PTATE XIII. 



