J. D. Dana—Reindeers in Southern New England. 358 
If the exact weight of the counterpoise kno be represented 
by a, then 
es = weight of mineral in air. (1) 
Also —P weight of mineral in water. (2) 
()a)="- Te = 0)? x weightol water digiaenl 
as 
(1)+(3)= _ 2D _ = =specific gravity of mineral. 
bp 
Hence the specific gravity is known if the ratio is known. 
This ratio is indicated upon the arm ab for as many points as 
possible. 
Worcester, Mass., Aug. 30, 1875. 
Art. XLVIIL—On Southern New England during the Melting 
of the Great Glacier ; by JAMES D. Dana. No. IIL. 
IIl.—Reinprers iv Sovurnern New Encuanp. 
THE beds in the vicinity of New Haven pertaining to the 
Champlain or Fluvial period of the Quaternary have recently 
auorded remains of mammals. I am unable to prove posi 
recently discovered I here briefly repeat the facts respecting its 
Position and relations. 
* Transactions of the Connecticut Academy, vol. ii, 1870, p. 84. 
Am. Jour, Sc1.—Tuirp agate X, No. 59.—Nov., 1875. 
