[xviii. ] 



MESODON. 



Fig. 5, 6, 7. M. ALBOLABRis, Say. Nicholson's Encjc, 

 p. 181, t. 1, f. 1, 1816. 

 Say, Am. Conch., t. 13, April, 1831. 

 Binney, Terr. Moll., ii., p. 9'9, t. 2, 1851. 

 Bland, Ann. N. Y. Lye, vi., p. 359, Sept., 

 1858. 

 ' W. G. Binney, 1. c, p. 43, 1859. No. 10. 



" 8. M. EXOLETA, Binnev. 1. c, p. 121, 1. 10, 1851. 

 W. G. Binney, 1. c., p. 54, 1859. 

 JI. zaieta, Binney. Bost. Jour. N. Hist., i., p. 



492, t. 20, May, 1837. No. 1. 



*' 9. M. DENTIFERA, Binney. Bost. Jonrn. Nat. 

 Hist., i., D. 494, t. 21, May, 1837. 

 Binney, Terr'. Moll., ii., p. 134, t. 12, 1851. 

 W. G. Binmy, 1. c, p. 55, 1859. No. 2. 



" 10. M. Wheatleyi, Bland. Ann. N. Y. Lye. 



Nat. Hist.,vii.,t.4,f. 7, Dl^c, 1H61. No. 8. 



" 11. M. Christyi, Bland. Ann. N. Y. Lvc. Nat. 



Hist., vii., t. 4, f. 5-6, Dec, 1861. No. 4. 



. IIELICIDiE. 



Synonymy and Reference to 

 Plate 8. 



MESODON. 



Fig. 1. M. THYROIDES, Say. Jour. Acad. Nat. Scien- 

 ces, i., p., 123, Oct., 1817, ii., p. 161, Jan., 

 1821. 

 Say, Nicholson's Encyc, 1818. 

 Say, American Conchologv, p. 13, Apr., 1831. 

 Bianey, 1. c, p. 129, t. 11, 1851. No. 



