320 PROCEEDINGS OF THE ACADEMY OF [May, 



are larger than those from the edge of the thicket where cover is 

 poor and periods of activity and growth fewer or shorter. A great 

 many, if not all, mere color variations may fall into the same class, 

 though sometimes color differences may be correlated with other 

 undiscovered differences. As for selecting abnormal specimens 

 which completely grade into the typical form in the same colony 

 and giving to them varietal names, as was done by Hemphill and is 

 now being done by various authors, the value to science of such a 

 practice is doubtful. 



Colton, 4 in discussing the genus Lymncea, protests against its 

 generic subdivision, but adds: "Species and minor groups on the 

 other hand cannot be too much subdivided. It is an advance to 

 describe every variation that can be distinguished." Probably no 

 one would object to the describing of all distinguishable variations, 

 but there is room for grave difference of opinion as to the advisability 

 of naming all such variations, which Colton seems to advocate in 

 quoting with apparent approval the following from Bateson: "They 

 will serve science best by giving names freely and by describing 

 everything to which their successors may possibly want to refer and 

 generally by subdividing their material into as many species as they 

 can induce any responsible society or journal to publish." It is 

 quite possible to carry the naming of species and varieties altogether 

 too far, especially in such a genus as Oreohelix. One may easily, 

 by taking averages of color, form and size, make a score of colonies 

 of 0. strigosa depressa into as many distinct varieties, which, when 

 seen in the mass and compared with each other, could be vaguely 

 distinguished, but when compared with all the colonies from which 

 we have collections would be quite indistinguishable, and not at all 

 distinguishable from each other with only a few specimens in hand. 

 Of such is Hemphill's "var. carnea." 



A nearly complete suite of the material upon which this report is 

 based has been placed in the cabinet of The Academy of Natural 

 Sciences of Philadelphia. 



The Tintic Mountains. 



This is a range of irregular outlines covering considerable territory 

 just west of central Utah. It was hitherto conchologically unex- 

 plored, and as we spent but one afternoon collecting here and made 

 but one station, it would doubtless well repay further exploration, 



4 Nautilus, XXVIII, 118. 



