1905.] NATURAL SCIENCES OF PHILADELPHIA. 245 
behind the lip there are fine, sharp strie. The embryonic whorl is 
glossy, with fine radial strize on the outer side of the suture ; some part or 
parts of the third or fourth whorls are sculptured with very minute raised 
“points in quincuneial order. The spire is low conic-convex, very obtuse 
above, the first two whorls being almost in a plane. Whorls 63 to 63, 
very narrow, and very slowly increasing; the first three are convex, those 
following being decidedly flattened, only slightly convex. The last whorl 
és acutely angular at the periphery, the angle more obtuse on its last 
third. The base is convex. The suture descends a little to the aper- 
ture. The lip is preceded by a creamy stripe, and the base is deeply 
guttered behind the expansion. The aperture is very oblique, narrow 
and lunate, obstructed by four teeth: a more or less sinuous, oblique 
parietal lamella, two compressed, entering teeth on the basal lip, of 
which the outer one is higher and more compressed, and an oblique, 
square-topped tooth within the outer lip. The sinus or notch between 
the two basal teeth is slightly wider than that between the outer basal and 
the outer lip tooth. The umbilicus is about one-sixth the diameter 
of the shell. 
Alt. 14.3, diam. 6.5 mm, 
eee Shige fe) FGtot | 
ao Vseoyt | cer Ore 
& 13, “ 6 “ 
if 13, (a9 6 “ee 
Two other specimens of the type lot measure 14 and 14.3 mm. 
diameter respectively. 
Chiricahua Mountains, Arizona, in the South Fork of Cave Creek, 
at the base of the mountain. Types No. 87,019, A. N.5. P., collected 
by Mr. Ferriss, February, 1904. 
The young shells show the characteristic punctation better than 
adults. At resting periods in the neanic stage of growth a callous rib 
is formed within the lip. When this occurs early (as in the specimen 
figured, Pl. XI, fig. 11, 8 mm. diameter) the rib is much thicker in 
the middle. When it occurs in the last whorl it is more equally 
thickened. , 
This species is closely related by shell characters, but not by its soft 
anatomy, to A. levettei angigyra of the Huachuca range, agreeing with 
that form in the close convolution of the whorls, the angular periphery 
and the general arrangement of the teeth. But all fresh specimens of 
A. angulata show a quineuncial punctation of some part of the neanic 
whorls, not present in the Huachuca form, and the two especially 
differ in the shape of the whorls, the upper surface of which is flattened 
