the species, Achatinella apexfulva Dixon, Welch discriminated 

 seventy-eight named subspecies and more than sixty unnam- 

 ed varieties, the majority based upon local populations differ- 

 ing mainly in slight deviations of color. It seems unfortunate 

 that the literature should be burdened with such extensive 

 taxonomic terminology to describe what is essentially an 

 interesting biological phenomenon illustrating one phase of 

 organic evolution. It indicates clearly however, the difficulty 

 under which taxonomic science suffers in dealing with a prob- 

 lem of this type. 



Another striking example of molluscan forms exhibiting 

 polytypic tendencies is seen in the terrestrial snails of the 

 genus Cerion inhabiting the coastal areas of the Bahamas, 

 Cuba, Haiti and Porto Rico, where large numbers of localized 

 races have been found. As usual in such cases the taxonomic 

 history is replete with superfluous names. 



in dealing with the nomenclatorial problems arising in con- 

 nection with the discrimination of polytypic forms we find 

 in the case of the mollusks a situation which is not commonly 

 found in other groups of invertebrates. 



The curator of a museum having a collection of molluscan 

 shells in his charge naturally desires to have his specimens 

 properly labelled, and for this purpose he depends upon the 

 specialists in the several groups. He finds wide disagreement 

 among the experts, and as he sadly changes his labels discovers 

 the truth of the bon mot attributed to Dr. G. VV. Wharton, 

 (Allen, 1955) **, the common names of animals change from 

 place to place, the scientific names from time to time." 



Taxonomists dealing with the systematics of groups of 

 mollusks exhibiting polytypic tendencies often find difficulty 

 in expressing the relationships of the several forms, and usu- 

 ally resort to trinomials. In monographing such groups the 

 older literature is apt to be obscure, with resulting confusion 

 and the accumulation of many synonyms, together with the 

 changing of many labels. 



