132 PROCEEDINGS OF THE ACADEMY OF [Feb.. 



Chiefly or wholly found at high elevations, and very rare in the region 

 north of Cave Creek. 



E. fulvus alaskensis differs chiefly from fulvus by having about one 

 whorl less in shells of similar size. On the first whorl the radial striae 

 begin at the first fourth, and are about as close as on the rest of the 

 shell. There are no spiral striae on the first or later whorls. The 

 last whorl has 90 to 105 striae in 1 mm. E. /. alaskensis was described 

 from Dyea Valley, Alaska. It is also before us from Petropavlovsk, 

 Kamchatka, collected by Dr. William H. Dall. It extends southward 

 in the Rocky Mountains to the Chiricahua and Huachuca ranges, in 

 southern Arizona, chiefly at high elevations. 



Fig. 26. — Euconulus fulvus alaskensis Pils. A, B, cotype, Dyea Valley, Alaska; 

 C, Head of Cave Creek, Chiricahua Mountains. 



Mr. E. G. Vanatta has made a careful study of the American forms 

 of Euconulus fulvus in order to determine the status of the Chiricahuan 

 form, using high magnification to bring out the minute sculpture. 

 It appears that all the forms examined have a minute sculpture of 

 excessively close, regular vertical striae, though in some examples 

 it is less distinct than in others. This sculpture, when strongly 

 developed, lends a silk-like luster to the surface in quite fresh examples. 



In E. fulvus from the northeastern United States the first whorl has 

 fine spiral striae and very indistinct traces of vertical (radial) striae, not 

 seen in some but legible, though weak, in other examples. The upper 

 surface of the last whorl has about 126 vertical striae in 1 mm., crossed 

 by spiral striae. There are about 6 whorls (figs. 27, b, c, Herkimer 

 Co., N. Y., No. 59,521 A. N. S. P., alt. 2.4, diam. 3.1 mm. Fig. d, 

 Buckfield, Oxford Co., Maine, No. 87,302 A. N. S. P., alt. 3.5, diam. 

 3.4 mm.). The largest examples seen are from Buckfield, Me., 

 collected by Mr. J. A. Allen. 



An English example (fig. 27a, Burnley, England, R. Walton coll., 

 75,912 A. N. S. P.) has distinct vertical striae on the first whorl as well 

 as spirals, and on the last whorl there are 140 vertical striae in 1 mm., 

 with no noticeable spirals. Alt. 2.4, diam. 2.8 mm. 



