TO COLLECTORS 
I have a few fine, perfect Specimens of P ADEE 
Argo (paper Nautilus), about 2% inches, at $1.00 each. 
Also a large number of rare, scarce shells. 
List submitted on application. 
J. F. POWELL, Waukegan, Ill. 
MARINE BIOLOGICAL SUPPLY DEPARTMENT 
Preserved material of all types of ae, = Class 
work or for the museum. For sg 
and all information, addres 
_ GEO. M. GRAY, CURATOR - - WOOBS HOLL, Mass. 
DISSECTI NG MICROSCOPES 
of every size, style and price, suited 
for all kinds of work. 
A new series of lenses 
for dissecting work have 
recently been perfected by 
us which have unusually 
long working distance and 
large flat field. These 
lenses are offered at 
prices less than any lenses of equal quality heretofore 
in use. The new Dissecting Stands are all nickeled 
metal with glass stage. ~ Catalog free. 
Sample copy JOURNAL OF APPLIED MICROSCOPY on request. 
BAUSCH & LOMB OPTICAL co. 
ee Btreata, 
25th Street m ioci E ROCHESTER, N. Y. — Piae d ; 
Lens Holder for Anatomical 
The only machine ever invented which will add — 
all the columns at one “hx M tip simple ss 
d more. ae 
Be eee dece ever invented which multiples ^ 
A a ry APP 
THE ONLY MACHINE | | | 
