i, Ml A". 



MANUAL OF CONCHOLOGY. 



Vol. JLIIBUL1MUL1DJE. 



Genus DRYM^EUS Albers. (Continued.) 



II. SPECIES OF THE WEST INDIES, TRINIDAD AND FLORIDA. 



With the exception of D. undulatus and D. elongatus and its im- 

 mediate allies, the Drymczus species of this area form a homogeneous 

 group, undoubtedly derived from the group of allied forms in Vene- 

 zuela and the adjacent region, which has the same characters. There 

 are also a few species in eastern Mexico belonging to the same group. 

 While some of the species have the expanded lip of typical Drymcem, 

 others have no perceptible expansion, and would technically be classed 

 in Mesembrinus ; but the distinction here is purely artificial, and had 

 better be disregarded. With an identical pattern of sculpture, the 

 various forms show gradations in texture from the excessive fragility 

 of D. dominicus to the solidity of D. liliaceus. In the more fragile 

 forms, the upper whorls of the spire usually exhibit an excessively 

 dense and minute granulation, below the grated apical portion. 



The land snails of the Lesser Antilles are in large measure peculiar 

 to the region ; and though there are conspicuous exceptions, the local- 

 ities on the mainland of South America which authors quote for them 

 are to be received with great caution. There can be no doubt that 

 many such records which have been copied by Pfeiffer in the Mono- 

 graphia, and thence by Mr. Smith in some of his valuable Antillean 

 lists, were based upon errors of determination or false locality labels. 

 Drouet has been particularly unfortunate in the introduction of such 

 errors, and except where the extrinsic evidence corroborates the state- 

 ments in his " Terrestrial and Fluviatile Mollusks of French Guiana," 

 I do not consider them worthy of quotation. Among the snails cred- 

 ited by him to Guiana, there are many species such as Helix nuxden- 

 ticulata, dentiens, Isabella, badia, orbiculata, Bulimus perversus, papy- 



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