378 The American Geologist. Doceniber, is9 
Faso county, Texas, and from larger specimens of the same 
from the ('omanche Peak limestone of central Texas. The 
Texas specimens have the concentric raised lines and strije 
crowded over the entire hight of the valves, while the concen- 
tric striae on the lower part of the valves of the Kiowa shells 
are separated by ribs of considerable breadth. 
Rou(hilri(i securiformis (formerly called Triyonia scriiri- 
forviis), of whicli BoHdalrin (iiiadrmts is a synonym, is a 
species of tlie (Jomanche Peak limestone. 
The shell that the writer describes elsewhere as C miriiiicrln 
fexava^ var. kloini ixi, is probably not different from the form 
so abundantly represented by casts in the Comanche Peak 
limestone, agreeing with these and differing from the 
casts of the typical (' iniriiiicrld fexuiid (which occur in a 
horizon between the Exo(i;ira te.ratxr bed of the Fredericks- 
burg and the principal Exogyra texana bed of the Bosque) in 
size and apparently, though perhaps not constantly, in con- 
vexity. It is probable that most of the specimens of CyprJ- 
nieria from the upper divisions of the Comanche also belong 
to the variety, l-l<>ir<ni(i. 
Plioladoiaya saiK'fi-salxv ranges from the Fredericksburg to 
the Denison division. It is the small form, like that of the 
Kiamitia clay of Indian Territory, rather than the large, 
coarsely ornamented one of the Denison beds, that occurs in 
the Kiowa shales. 
The Corbnhi crusslrostntd of the Kiowa shales is probably 
the same Corbuhi that is common in the Denison division, as 
the writer noted under the original description of the species. 
It is one of the most abundant of the fossils of the Pawpaw 
beds. 
Trochiis texdinis in Texas is known only from the Barton 
Creek limestone of the Fredericksburg division. 
The originally described variety of Tttrrt fella serlatlin-yran- 
ulata is a small phase that presents one extreme of size in 
this species and is characteristic of the upper Glen Rose beds 
at Fredericksburg. The commonest and, as to size, the cen- 
tral variety of the species, var. /,'(iiisas<')isis, found so i)ro- 
fusely and in so excellent preservation in tlie Kiowa shales 
(especiall}'^ in the lower part of the Blue Cut zone and in the 
Mentor beds) is the same that occurs in the Comanche Peak 
