Elrod, M. J. 1901. Montana shells. Rocky Mountain Magazine 2:691-697. 



Elrod, M. J. 1902. A biological reconnoissance in the vicinity of Flathead Lake. University of 



Montana Bulletin No. 10, Biological Series No. 3. 

 Elrod, M.J. 1903a. Notes on Pyramidula elrodi Pils. The Nautilus 16:109-1 12. 

 Elrod, M. J. 1903b. Montana shells- Pyramidula strigosa . The Nautilus 17:1-6. 

 Fairbanks, H. L. 1984. A new species of Oreohelix (Gastropoda: Pulmonata: Oreohelicidae) 



from the Seven Devils Mountains, Idaho. Proceedings of the Biological Society of 



Washington 97:179-185. 

 Frest, T. J., and E. J. Johannes. 1995. Interior Columbia Basin mollusk species of special 



concern. Final Report to Interior Columbia Basin Ecosystem Management Project. 



Deixis Consultants, Seattle. 274 pp. 

 Goodfriend, G. A. 1986. Variation in land-snail shell form and size and its causes: a review. 



Systematic Zoology 35:204-223. 

 Pilsbry, H. A. 1939. Land mollusca of North America (north of Mexico), volume 1 part 1. The 



Academy of Natural Sciences of Philadelphia, Monographs Number 3. Philadelphia. 573 



pp. 

 Sokal, R. R., and F. J. Rohlf. 1981. Biometry, second edition. W. H. Freeman, San Francisco. 



859 pp. 



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