1915.] NATURAL SCIENCES OF PHILADELPHIA. _ 341 
Also one shell which has two basal lamellae. The upper partition 
was broken away in opening, so that the presence of a superior 
lamella is uncertain. 
This form stands nearest to H. b. mearnsi, but the striation is 
sharper, not partially effaced on the later whorls and the cone is in 
the average longer. The habitats of mearnsi and media are rather 
remote from one another, and several other forms inhabit territory 
between them. 
The specimens from Station 12 are more like mearns?, the sculpture 
being weak on the penultimate and next earlier whorls. Out of 
11 opened— _ 
~ 2 have one lamella, axial. 
9 have two lamelle, axial and basal. 
1 has three lamelle, axial, basal and superior. 
Station 2 is on the northern slope of one of the ravines east of 
and running from Teocalli Butte, at the foot of an irregular pro- 
jecting bench of limestone. It is much the lowest station where 
shells were found in the Hachetas. The shells are partly as rough 
as those from Station 3, but some approach those of Station 12. 
Out of 21 shells opened— 
15 have two lamellze, axial and basal. 
6 have three lamelle, axial, basal and superior. 
In size the shells from Stations 12 and 2 are about equal to those 
from Station 3. 
Holospira bilamellata mearnsi Dall. Plate VII, figs. 6, 6a. 
Holospira (Haplostemma) mearnsi Dall, Proc. U.S. Nat. Mus., XVIII, 1895, 
p. 4; XIX, 1896, p. 350, Pl. 31, fig. Le 
Holospira (Distomospira) mearnst Dall, Bartsch, Proc. U. S. Nat. Mus., 
XXXI, 1906, p. 134. 
Six shells of the type lot, the measurements of which are given 
by Dr. Bartsch, measure 14 to 15.8 mm. long, 4.2 to 4.5 wide, with 
14 whorls. Twenty shells were taken at our Station 8, on the 
eastern slope of Hacheta Grande Mt. (see map, p. 325). Ten were 
opened, 3 having only the axial lamella, which is very weak in two 
of them; 7 have axial and basal lamellae. Measurements follow. 
Length 17, diam. 4.5 mm. ; whorls 15; an axial lamella. 
15; aetna) 15; axial and basal lamelle. 
ee ame ben Res) iz By) fF - 141 
Pe rgilcio ke Aaa ff ro 14 
ae calle patens* eae axial and basal lamelle. 
ce 13; iz 4 ce a3 131: 73 ce 
ce 13, 73 4 a3 73 13 ce iz3 ce 
“ec 13, 73 3.9 ce iz 123; ce ce ce 
