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PROCEEDINGS OF THE ACADEMY OF [NoV.-DeC, 



The Blue River series shows all gradations of shape between very- 

 high shells, those of the typical cooperi contour, and an openly um- 

 bilicate shell with whorls of small caliber. The sculpture varies from 

 that of Black Range cooperi to more effaced, the striation and spirals 

 weak. 



Fig. 14. Genitalia of Oreohelix cooperi. a, Gosper's pasture; b, Blue River, 

 Station 26; c, form apache, Black River, Station 81. 



The genitalia (figs. 14a, h, c) agree with those organs in 0. cooperi 

 from the Black Range, N. M., figured in these Proceedings for 1917, 

 p. 101, fig. 5. The internally ribbed portion of the penis forms more 

 than half of the total length of that organ, as in all forms of 0. cooperi. 

 Measurements in mm. follow. Numerous other specimens opened 

 but not measured were seen to agree with those illustrated. They 

 are distinguishable at sight from all forms of 0. strigosa. 



Preparations are figured from Stations 26, Blue River (fig. lib), 58, Gosper's 

 pasture (fig. 14.i) and 81, Black River (fig. 14"). The specimen dissected from 

 Station 36 is an albino. 



