274 PROCEEDINGS OF THE ACADEMY OF [Mch., 
bryonic whorls in the least worn shells; broadly two-banded with chest- 
nut, blackish in places, the upper band sometimes extending to the 
suture. 
Alt. 9 8.7 10 mm. 
Diam. 15,2 15 Deg 
3. Limestone Mountain, Huachueas, south side at 8,000 fect eleva- 
tion (Pl. XXIV, figs. 29-31). The shells are whitish with some fleshy 
or livid streaks or dots, and with two bands, or clouded and suffused 
with purple-brown. Similar to typical concentrata except that the 
umbilicus is decidedly smaller within. The last whorl descends to the 
aperture. They are like O. s. hwachucana, No. 3, from Brown Canyon, 
in miniature. They are rounded or slightly angular in front. The 
sculpture is subobsolete, without a trace of spirals. 
Alt. 8.9 8.4 9.5 mm. 
Diam. 15.2 15's 15 ad 
Whorls 5 4} 5 
Scalariform monsters are not rare, but the inception of that abnormal 
condition seems to be invariably traceable to an injury of the shell. 
One such is figured (Pl. XXIV, fig. 31). 
4, Limestone Mountain, south side, 8,000 feet. Like the preceding, 
but more elevated and fleshy white with pinkish apex. The last whorl 
descends rather deeply (Pl. XXIV, fig. 32). 
Alt. 10 9.7 8.7 mm. 
Diam. 15.3 15.5 VE 
5. Limestone Mountain, north side, 8,000 feet. Similar to the two 
preceding lots in size and sculpture, but broadly two-banded with 
purple-black, or entirely of this color (Pl. XXIV, figs. 25, 26, 27). 
This lot resembles O. s. hwachucana, Nos. 11, 12, from Carr Canyon, 
which are also from a high altitude. No. 5 from 7,000 feet, Brown 
Canyon, has also similar coloring, but is much larger. 
This lot, like all seen from Limestone Mountain, does not have the 
umbilicus so wide within as in typical concentrata. 
Alt. 9 8.8 9.3 mm. 
Diam. 16.3 15.5 5 
6. The series of five specimens sent by Dall as O. s. concentrata from 
Haeheta Grande Mountain, Grant county, New Mexico, one of which is 
figured on Pl. XXV, fig. 60, shows no appreciable divergence from the 
