HELIX. 147 



23. HELIX MONODON, RACKETT. 

 PLATE XLI. 



H. testa convexiuscula, umbilicata, sive imperforata, 

 corneo-fuscescente, hispidula, tenuissime striata ; apertura 

 semilunata ; labro albo, margine angusto, reflexo ; dente 

 unico albo, longo, compresso, ad columellam oblique ad- 

 nato ; regione umbilical! impressa. 



SYNONYMS AND REFERENCES. 



Helix monodon, RACKETT, loc. cit. XIII. 42, pi. 5, f. 2. 



WOOD, loc. cit. Supplem. pi. 7, f. 15. 



BINNEY, Bost. Journ. Nat. Hist. III. 360, pi. 10, f. 1. 



GOULD, Invertebrata, 174, f. 113. 



ADAMS, Mollusca of Vermont, 9. 

 Helix fraterna, SAY, Exped. St. Peters, II. 257, pi. 15, f. 3. 



KIRTLAND, Ohio Report, 173. 



SAGER, Michigan Catalogue, 14. 



BINNEY, Boston Journ. Nat. Hist. III. 363, pi. 10, f. 2. 



DE KAY, New York Report, 31. 

 Helix convexa, DESHAYES in Lamarck, VIII. 112. Eiicyc. Meth. II. 253. 



FERUSSAC, Hist. pi. 50, a. f. 2. 



CHEM. 2ed. t. 10. f. 17, 18; t. 66. f. 24-27. 



PFEIFFER, Monog. Helic. Viv. I. 420. 



DESCRIPTION. 



ANIMAL yellowish brown, darker on the head, neck, 

 aud tentacles. Foot narrow, cylindrical, one and a half 

 times as long as the diameter of the shell, terminating in 

 a point. Superior tentacles one-fourth of an inch long. 

 Eyes black. Some individuals much darker than others. 



SHELL slightly convex ; epidermis varying from light 

 russet to chestnut color, with numerous very minute, 

 hairy projections ; whorls five to six, narrow, diminishing 

 very gradually in width from the outer whorl to the 



