In view of the transitional state in which the science of sys- 

 tematics finds itself, it is not surpising that much variance 

 exists in the treatment of taxonomic material. As yet no Moses 

 has appeared to lead us out of the nomenclatorial wilderness. 



Some authors have suggested that in such cases we should 

 abandon the Linnean system and resort to the use of num- 

 bers to identify the various related forms. Others, as in the 

 case of those attempting to record the protean variations in 

 the shell banding of the garden snail Ce-pea hortensis^ have 

 resorted to the use of cabalistic insignia, which make their 

 reports resemble the formulae of differential calculus. 



In general the tendency among sytematists dealing with in- 

 vertebrate groups has been to follow the procedure initiated 

 by the ornithologists and mammalogists and reduce many of 

 the recorded species to subspecies, and place others in the syn- 

 onymy. Goodrich (1922) in an early paper dealing with the 

 river snails of the genus Anculosa inhabiting the watershed of 

 the Alabama River listed some thirty species, but in a later 

 paper (1945) treating of the widely distributed and locally 

 variable fresh-water snails of the genus Goniohasis inhabiting 

 the area between the Great Lakes and New York, recognized 

 the clinal relation of these forms and reduced a list of over 

 twenty trivial names to a single species, Goniohasis liuescenSy 

 and gives illustrations of eighteen divergent local races. 



In a recent paper Herrington (1954) has presented a revis- 

 ion of the American forms included in the genus of small fresh- 

 water bivalves Pisidium. He reduces the number of listed 

 species from about one hundred to twenty-five. Of these only 

 three are limited in their distribution to the United States, 

 while twelve are circumpolar. 



A classical example of the difficulties that arise in attempt- 

 ing to give systematic expression to a clinal group of molluscs 

 is the case of the tree-snails of the family Achatinellidae in- 

 habiting the Hawaiian Islands. The richly colored shells of 

 these molluscs were early brought to the attention of collec- 

 tors following the discovery of the islands by Captain Cook 



