encircled by a rather wide dark chestnut band above the periphery, bordered above and below with whitish bands. The spire is low conic. Whorls 5-1/4, slowly increasing to the last, which is much wider, and descends rather deeply in front. The embryonic shell consists of l i whorls. The first half whorl has radial wrinkles, and begins in a smooth tip; then a small areolate area follows, after which there are curved, forwardly descending delicate threads reaching the suture below, but weak or obsolete on the summit of the whorl, which is irregularly roughened; there are also some forwardly ascending threads in places. The first neanic whorl has sculpture of slight growth ripples and an indistinct roughening or punctation. Subsequent whorls are lightly marked with growth-lines only. The aperture is very oblique, subcircular; peristome thin, a little expanded, narrowly reflexed below, the columellar margin dilated.
Height 15.2, diameter 25 mm.; aperture 11.7 x 13 mm.
Penis small, usually shorter than the vagina, and less than one-third as long as the spermatheca and duct. Epiphallus short, the flagellum apparently absent or reduced to a very minute adnate coecum (Fig. 174). Radula with 35, 1, 38 (summit of Cross J Mt.) to 38, 1, 38 teeth, about 14 laterals, an ectocone appearing on the 11th to 13th. The entocone is bifid on the outer 15 to 18 marginals, and the ectocone occasionally so on some teeth, though generally simple. Six radulae from 5 stations examined. The jaw has 5 ribs in two, 6 and 7 in two other examples. The crop and oesophagus as far as the stomach are conspicuously sulcate or corrugated longitudinally.
Arizona: Emigrant Canyon, Chiricahua Range, from about 4500 to 7000 feet1 (Pilsbry and Ferriss), Type 99784 A.N.S.P., from about 2 miles north of west of Rough Mountain, at about 6000 feet.
This handsome snail has a far wider umbilicus than S. bicipitis. It is much like S. hachitana, but differs by the shape of the verge and the
Fig. 174. S. optata. fl., flagellum.
1 These mountains had not been mapped at the time Ferriss and the author collected there. In our paper of 1910, p. 121, a rough map from the author's notebook shows the locations of our collecting stations. Our "Cross J Mt." (l. c. p. 87, fig. 12) and "Big Emigrant Ml." (local names obtained from ranchers), are Wood Mt. and Rough Mt. of the U.S.G.S. topographic map.
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