204 Cincinnats Society of Natural Fitstory. 
low rounded prominences near the dorsal edge where the converging 
ends of the ridge fail to meet, leaving a sulcus between them. 
As interpreted by me this species is near U. tuberculo-spinosa, J. 
and K., and J. emarginata, and distinguished from them by con- 
fluence of the bases of the tubercles which in those species are 
distinct. I am confident that the peculiarities of the species are to 
be accounted for in this manner, and that its affinities are with 
Ulrichia and not with Primitia. : 
Position and locality: Shales of the Chester group, near Gray- 
son Springs, Ky. 
BEYRICHIA RADIATA, Jones and Kirkby, var. CESTRIENSIS, n. var. 
Plate XLV. Fags 4. a0. 
Beyrichia radiata, Jones and Kirkby, Ann. Mag. Nat. Hist., ser. 
5, vol. 18, pl. Om tgse Inm2 "a2: 
Size: Without frill; length, 0.35 mm; heise. 
height with frill, 0-65 mm. 
The Chester shales specimens which I propose to designate as 
above, are too much like the original figures of 4. radiata to de- 
serve separation of greater than varietal importance. ‘They differ 
from the British examples in being a little higher, with the ends 
also more equal, the frill a little wider and extending more nearly 
on the same plane with the contact edges of the valves. The sur- 
face also is finely papillose all over, a feature that is not exhibited 
in Jones and Kirkby’s figures. ‘The large rounded lobes or tuber- 
cles also are of more ovate shape and less unequal in size. These 
differences may be of sufficient importance to establish the va- 
Tebya | 
Position and locality: Shales of the Chester group, near Gray- 
son Springs, Ky. 

*Since this was written I have looked over a small parcel of washings from 
shales at the extreme top of the chester in Caldwell County, Ky. Among 
others I detected three valves that seem to be zdezzca/ with the British types 
of B. radiata. This discovery goes to show that the var. cestrzemszs is not a 
mere local modification of the species. 
