MILLIPED GENUS CHEROKIA HOFFMAN 263 



as one examined only small samples of specimens, from widely sepa- 

 rated localities, such reasoning might have some appeal. It seems more 

 reasonable to me, however, to assume that such local variants are 

 nothing more than populations, perhaps sometimes subspecifically 

 distinct, of widespread polymorphic species. The phenomenon of 

 geographic variability in most species has been recognized and under- 

 stood for quite a long time. 



In disposing of "isogenitive species" as doubtlessly only the results 

 of localized microevolution, which is far from reaching the species 

 level, I note that even the term appears to be incorrectly formed, 

 presumably from the Greek "isos" (equal) and the Latin "genitivus" 

 (possessive case). From the usage of the word, the meaning iso- 

 genital was implied — "isos" + "genitalis" (of the sexual organs)— but 

 even this usage is objectionable because of its hybridity. 



The present study has shown that populations of one species may 

 be so divergent that, given only specimens of the t}'pical forms, one 

 would be justified in considering them specifically different. This 

 discovery should be of considerable aid in the evaluation of species 

 in large genera such as Rhysodesmus, in which the gonopods are re- 

 markably similar, and in which species have been erected on characters 

 such as size and color, and even then only by overlooking previously 

 named species from the same general regions. 



Literature Cited 



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