1905.] NATURAL SCIENCES OF PHILADELPHIA. 277 



of the base whitish, often dotted. Upper surface also dark brown, 

 usually with a light line below the periphery (PL XXIV, figs. 17, 18). 

 7,000 feet elevation. 



6. Ramsey Canyon, Huachuca Mountains, collected in 1904, and 

 evidently from a different colony from the types collected in 1902. 

 Two specimens received are dirty whitish. The whorl descends very 

 deeply to the aperture. They are markedly gerontic. 



Alt. 9.5, diam. 17.3 mm. 

 " 10, '' 16 " 



Carr Canyon, Huachuca Mountains. In this canyon most or all 

 colonies have the form with rounded periphery, and that with it acutely 

 carinate on the first half of the last whorl. The spire is usually sharply 

 striate obliquely, and the last whorl is frequently striate spirally. The 

 special tendencies of this canyon are most strongly expressed in No. 12. 



7. Carr Canyon, 5,500 feet. Similar to No. 4, Brown Canyon, except 

 that the sutures are less impressed, nearly level, and margined very 

 distinctly above by the keel. In some shells the last whorl is rather 

 distinctly decussate by spirals above. In one specimen the suture is 

 deeply deflexed above, as in the Ramsey Canyon shells. A basal 

 band is sometimes present. 



S. Carr Canyon, 5,500 feet. One specimen is similar to No. 7; the 

 other three, measured below, are more calcareous, resembling No. 2, 

 but the whorl is deflexed anteriorly (PI. XXIV, figs. 21, 22, 23). In 

 one the keel extends to the aperture, though rather weakly. 



Alt. 10 9.8 8.6 mm. 



Diam. 20 18.8 18.8 " 



9. Carr Canyon, 6,000 feet (figs. 19, 20). Shells like No. 3, Brown 

 Canyon, but not so white, the ground color being light brown, and the 

 oblique striation sharper. Two specimens show a second band on the 

 base. 



Alt. 11 12 11 10 mm. 



Diam. 19.8 19 18.7 17.4 " 



10. Carr Canyon, 6,000 feet (fig. 24). Similar to the preceding, but 

 the ground is much darker, like No. 4. Diam. 18.6 to 19.5 mm. 



11. Carr Canyon, 7,000 feet. Blackish-chestnut, the inner whorls 



