298 OBSERVATIONS ON THE 
Geometric Spiders for the purpose of suspension, 
it is obvious why they usually direct their heads 
downwards when they occupy the centre of their 
nets. 
As several difficulties present themselves in the 
prosecution of these researches, occasioned, chiefly, 
by the impracticability of comprising all the claws in 
one distinct view, I cannot completely satisfy myself, 
at present, whether the number and arrangement of 
the additional claws are uniformly the same, on the 
feet of such spiders as J have ascertained to be 
supplied with them, or not; though, as regards the 
larger species, I am thoroughly convinced that this is 
the case, and I have reason to think that it will ulti- 
mately prove to be so with the rest. 
It is not at all surprising that the Geometric 
Spiders, which employ their feet in the fabrication of 
complicated nets, should have them more amply pro- 
vided with claws than those species which use theirs 
principally as instruments of progression. An esti- 
mate of the number of viscid globules distributed 
on the elastic spiral line in a net of Epetra apoclisa 
of a medium size will convey some idea of the ela- 
borate operations performed by the Geometric Spiders 
in the construction of their snares. The mean dis- 
tance between two contiguous radii in a net of this 
species is about seven tenths of an inch; if, there- 
fore, the number 7 be multiplied by 20, the mean 
number of viscid globules which occur on one tenth 
