134 
THE GEOLOGIST. 
as at first. Mr. Lyell considers the time occupied by tlie reces- 
sion of the falls from the Whirlpool to be quite conjectural,, but 
assigns a foot, rather than a yard a year, as the more probable 
estimate. Thus he shows the mastodon, found on the right 
bank, near Goat Island, though associated with shells of recent 
species, to have claims to a very high antiquity, since it was bu- 
ried in fluviatile sediment before the falls had receded above the 
Whirlpool. 
2. Notice on a Suite of Specimens of Ornithoidicnites, or 
Footprints of Birds, on the New Red Sandstone of Connecticut, 
United States. By Dr. Mantell, F.G.S. 
These specimens were accompanied by a letter from Dr. Deane, 
of Greenfield (Massachusetts), the original discoverer of these 
curious footmarks, of which more than thirty varieties have been 
found, mostly bearing a striking resemblance to the tracks of 
living birds ; they are invariably those of a biped, and, in some 
instances, the progress of the animal may be followed over as 
many as ten successive steps. One example is fourteen inches 
in length. 
MISCELLANEA. 
Washingtonite — a New Mineral. 
Mr. Shepard, M.D. of the South Carolina Medical College, 
thus describes a mineral recently found near Washington, U.S. 
Fig. 1. Fig. 2. 
Primary form, rhomboid ; P on P = 86^, as determined by 
the reflective goniometer, on varnished planes. Plane o the 
most shining, P, the most briUiant. Tlie crystals, fig. 1, from 
