1905.] NATURAL SCIENCES OF PHILADELPHIA. 213 
Family UROCOPTID A: Pils. 
This family is represented in the Southwest by members of two very 
distinct subfamilies: EucALopIIN&® with the genus Holospira, and 
MIcROCERAMIN.® with the genus Microceramus. 
Holospira is an old genus, containing several highly specialized phyla. 
Our species fall into five groups as indicated below. The subgenera 
were formerly defined by the internal lamelle alone; but these are in 
some cases of less significance than the general form and sculpture. 
A.—Last whorl distorted, its last half turning sinistrally. 
I.—Internal column rather large, smooth throughout; last whorl 
sinuous, turning sinistrally. Aperture oblong, with a strong 
fold within the right margin and a vertical columellar cal- 
lous in the throat. Mrrastoma Strebel. One species, H. 
roemeri. 
B.—Last half of the last whorl straightened, normal. 
II.—Internal column small, smooth and simple throughout, or 
with a small axial lamella in the last whorl; very slender 
below, slightly wider above. Shell rather large, 19 to 29 
mm. long, the individual whorls comparatively high; the 
last one or two more coarsely sculptured than the inter- 
mediate ones. Number of whorls much less than the num- 
ber of millimeters in the length of the shell. Haplocion 
Pils. Species, H. pasonis Dall, H. hamiltona Dall. 
I1I.—Penultimate whorl with a short, stout lamella on the axis, 
and a weaker one on the basal wall. Number of whorls 
decidedly less than the number of millimeters in the shell’s 
length. Distomospira Dall. Species, H. bilamellata Dall. 
TV.—Internal column moderate, one-fourth to one-sixth the diam- 
eter of shell. Shell 9 to 18 mm. long in known species, com- 
pactly coiled, ribbed or striated, the whorls short, their 
number about equal to the number of millimeters in the 
length of the shell, or exceeding that number. A short axial 
lamella is present within the penult. whorl, and sometimes 
short basal or parietal lamelle. Bostrichocentrum Strebel. 
Type H. tryon. 
V.—Cavity of the penultimate whorl obstructed by four strong 
lamelle, axial, basal, parietal and palatal. Hotosprra 
s. str. Species, H. goldjussi Mke. 
In addition to the species noticed below, the following species of 
Holospira are known from north of the Mexican boundary: 
H. (Bostrichocentrum) pilsbryi Dall, rather doubtfully recorded from 
New Mexico or Arizona, without definite locality, and known to inhabit 
the Mexican state Puebla. 
H. (Distomospira) bilamellata Dall, from the top of Hacheta Grande 
Mountain, Grant county, New Mexico. 
