NATURAL HISTORY. 3 
bers, give it a novel and interesting aspect. 
The magnified view of the inferior side, given 
in plate 8, figure 2, exhibits a full-grown Satyr, 
as it is commonly seen on the side of a vessel of 
water in an upright position. 
The real length of the specimen represented 
in the drawing was the one hundredth of an 
inch. In the infant state they are much smaller, 
and their great transparency at this period ren- 
ders them highly valuable for the microscope. 
These creatures I have found most abundant 
in the spring, during the months of March and 
April. They may be taken in shallow pools of 
clear water, near the surface, among thriving 
aquatic weeds and plants, by means of a basin 
or cloth net. When the water is putrescent, or 
the vegetation in a state of decomposition, it 
will be useless to search for them. 
The back of this creature is covered with a 
delicate transparent shell, while the inferior side 
is unprotected and membraneous. Its appear- 
ance, when viewed in profile, much resembles 
that of the tortoise, and the under view, shewn 
in the drawing, is not unlike the form of a horse- 
shoe. Attached tothe lower part, and radiating 
as from acentre, are four legs and two antenne. 
In the middle, between the two latter, is posited 
E 
