Review of the New York Geological Reports. 169 
the flagstones of the middle part. As these have been extensively 
used for pavements in the towns and villages of the vicinity, 
fine specimens are often to be seen on the side-walks of the streets 
especially in Geneva and Pen-Yan. 
Hie 
Hh 
paydvad sopromng 
(POL) ‘“saodoy s,[[e]] pu s,woxnue, 
Hf) Lh Ha bE! He ‘ 
" i i y yin us 
The most common fossil shells in the inferior members of the 
group are embraced in the wood-cuts on the following two pages. 
ig. 1. Avieula speciosa is abundant in and characteristic of the 
Cashaqua shales. Fig. 3. B. expansus is thought to resemble 
an Upper Ludlow fossil figured in Murchison’s work, (fig. 32, pl. 
5.) The figures are too imperfect to enable one to form an opin- 
ion. Fig. 7. P. acutirostra is considered by Hall a peculiar form 
Szconp Seniss, Vol. II, No. 8.—March, 1847. 22 
