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 mearnsi, the sculpture 

 being weak on the penultimate and next earlier whorls. Out of 

 11 opened — 



2 have one lamella, axial. 



9 have two lamellse, axial and basal. 



1 has three lamellse, 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 lamellse, axial and basal. 



6 have three lamellse, 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 (Haplostenuna) mearnsi Dall, Proc. U. S. Nat. Mus., XVIII, 1895, 



p. 4; XIX, 1896, p. 350, PI. 31, fig. 1. 

 Holospira {Distomospira) mearnsi 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 lamellse. Measurements follow. 



Length 17, diam. 4.5 mm.; whorls 15; an axial lamella. 



