516 



REPOKT OF STATE GEOLOGIST. 



MIOROTUS PINETORTJM SCALOPSOIDES (Andiibon aiifl Bachman). 



MOLE MOUSE. 



Arvicola scalopsoides Audubon & Baehman, Proc. Acad. Nat. 



Sci. of Phil., Vol. I, p. 97, 1841. 

 Arvicola pinetorum Evermann & Butler (part), Proc. Ind. 



Acad. Sci. for 1893, p. 127. 

 Microtiis pinetorum scalopsoides Bailey, N. A. Fauna, No. 17, 



p. 64, 1900. 



(For diagnosis, description and measurements see the preced- 

 ing species.) 



Range. — This subspecies extends from southern New York to 

 Illinois, with a more northern range than the preceding. Indiana 

 localities are : Terre Haute, Brookville, Randolph County, Wa- 

 bash County. The last two records are from Evermann and Butler, 

 and are assigned to this subspecies for geographic reasons. I have 

 never taken these mice in the northern part of the State, and have 

 no measurements of my own. 



Remarks. — Admitting two subspecies of this group of mice to 

 the Indiana fauna is made necessary by Bailey who, in his revi- 

 sion of the genus, records the two forms from Brookville. Such 

 a procedure may be necessary to the systematist who wishes to as- 

 sign all of his specimens to one form or another, and at the same 

 time be consistent in observing the characters which define the 

 forms; but it is wholly at variance with the true conception of 

 species and subspecies. If subspecies are to be considered as all 

 derived from an ancestral form by a process of variation, the 

 variations becoming fixed by climatic or other direct influences, 

 or geographic isolation, it is unthinkable that two of these sub- 

 species should be found in the same locality. It is conceivable, of 

 course, that where they intergrade there should be a neutral zone 

 in which some individuals should be like one and some like the 

 other subspecies, but these are all neutrals or else the forms do 

 not intergrade and hence are not subspecies. The Linnaean sys- 

 tem of nomenclature is inadequate to express such relations. 



It should be stated that the same differences which Bailey recog- 

 nized in Brookville specimens are to be seen in those collected at 

 Mitchell. Number 150, author's collection, is small and of a rich 

 glossy brown color as found in auricularis. Number 259 is decided- 

 ly larger and duller as in scalopsoides, and there are other speci- 

 mens showing the same differences. 



Hahits. — The habits are not known to differ materially from 

 the other form. 



