HELIX. 129 



16. HELIX THYROIDUS, SAY. 

 Plate XI. 



H. testa orbiculato-convexa, sub-umbilicata, luteo-cornea ; 

 anfractibus tenuiter striatis, striis confertis, obliquis ; appen- 

 diculo dentiformi, obliquo, columelte adnato ; peristomate 

 albo, margine reflexo. 



SYNONYMS AND KEFEEENCES. 



Helix thyroidus, Say, Nich. Eacyo. (Amer. ed.) IV. 



Journ. Acad. I. 123, II. 161. 



American Concliology, No. 2, pi, 13. 

 Feeussac, Hist. pi. 49, a. f. 4 ; pi. 50, a. f. 6. ? 

 Deshayes, Encyc. Meth. II. 230. 

 Lamarck, An. sans Vert. 2 ed. VIII. 114. 

 Sager, Michigan Catalogue, 14. 

 BiNNEY, Bost. Jour. Nat. Hist. I. 4S8, pi. 18. 

 De Kay, New York Report, 31. 

 Gould, luvertebrata, &c., 171, pi. 108. 

 Adams, Mollusoa, &c., 9. 

 Hdix thyroides, Pfeiffee, Monog. Helic. Viv. I. 356. 



DESCRIPTION. 



Animal. Color a dirty yellowish -white, with a grayish 

 hue in some individuals, tentacles darker, eyes black, 

 base of foot dirty white ; foot rather narrow, terminated 

 posteriorly in an acute angle. Length equal to twice 

 the breadth of the shell. 



Shell rounded, convex; epidermis, of a uniform 



yellowish brown or russet color ; whorls five, with fine, 



parallel strite, running obliquely across them ; suture 



distinctly impressed; aperture rounded, contracted by 



VOL. 11. 33 



