52G 
SUPPLEMENT 
having mandibles and palpi ; and from the plioxichili, because 
their mandibles are forceps-like or didactylous. 
The nymphons are, of all the pycnogonides, those whose 
body and feet are most slender and most long. They also 
differ in the form of the first articulation of the body, which 
may be considered as the head : it is proportionally longer, 
and more narrowed in the middle. The sucker is cylindrical, 
which is likewise the case with the phoxichili, but not with 
the pycnogona, when this part has the form of an elongated 
cone, and truncated at the point. The two neighbouring feet 
in the females have two intermediate articulations, much 
longer than the others, and curved. The external and general 
organization of the nymphons, being otherwise similar to that 
of the other araclinida of the same family, it would be super- 
fluous to dilate upon it here. Of their history nothing parti- 
cular is known. 
In the third family of Trachean Araclinida, that of Hole- 
tra, we have now to treat of the genus PHALANGIUM. 
The plialangia are very remarkable for the length of their 
feet. The first naturalists who wrote upon these insects called 
them long-legged spiders ; but they differ from the spiders, 
not only in their internal organization, but also with respect 
to the general form of the body, the number of the eyes, the 
parts of the mouth, and the mode of living. They are to be 
seen every where. In the country they may be found upon 
plants, and also are observed in houses, upon plastered walls, 
to which they are fond of hooking themselves. 
Their body is ovoid or rounded, often depressed, and 
enclosed beneath a skin slightly coriaceous. Their corslet, 
the anterior of which is angular, and which is about one-third 
and a half of the length of the body, is separated from the 
abdomen only by a transverse line. This abdomen is covered 
with a skin of a single piece, forming several folds, which 
mark the rings. It has a stigma on each side, near the origin 
