50 INTRODUCTION. 



In tlie last-named papei-, M. Rafincsque describes 

 two species of Agatina, for such was the orthography 

 he adopted for Achatma. 



^^ Agatina variegata. Baf. 1820. Six spires, smooth, yel- 

 lowish, variegated with brown spots near the sutures, first 

 spire with some narrow colored strias, concentric. Nearly 

 two inches ; from Louisiana. 



" A -fuscata. Raf. 1822. Eight spires, smooth, reddish 



brown, with broad longitudinal black bands on the spires, 

 of a lanceolate flexuose shape. Over two inches ; from 

 Texas." 



Persons acquamted with our Hehces, will readily 

 distinguish nearly all the species on which M. Rafin- 

 esque founded the above genera, for it is apparent that 

 he had actually before him American specimens, and 

 did not depend upon liis memory or imagination. It is 

 singular, however, that with his fondness for publisliing 

 species with the contraction " i^a/." appended, he 

 nowhere described these Helices. Descriptions may, 

 indeed, exist unnoticed in some of the loose fragments 

 which heralded his pretended discoveries ; but this is 

 not hkely. The probable explanation of the fact is, that 

 he became acquainted with most of the species in Phila- 

 delpliia, (m the Aviuter of 1818 and 1819, after his 

 return from his first visit to the West,) where they had 

 already been announced by Mr. Say: a supposition 

 which is supported by the fact, that in two letters from 

 him to the New York Lyceum, pubhshed in the Ameri- 

 can Monthly Magazine and Critical Review, in Septem- 



