ARACHNIDES. 
279 
FAMILY 1. 
ARANEIDES. 
This family is composed of the genus Aranea, Lin., or the Spiders. 
They have palpi resembling little feet, without a forceps at the end, 
terminated at most in the females by a little hook, and the first joint 
of which, in the males, gives origin to various and more or less com- 
plicated sexual appendages* * * § . Their frontal chelicerae (the mandibles 
of authors) are terminated by a moveable hook, flexed inferiorly, 
underneath which, and near its extremity, which is always pointed, is 
a little opening, that allows a passage to a venomous fluid contained 
in a gland of the preceding joint. There are never more than two 
jaws. The ligula consists of a single piece, is always external and 
situated between the jaws, and either more or less square, triangular, 
or semicircular. The thoraxf usually marked with a depression in 
the form of a V, indicating the space occupied by the head, consists of 
a single segment, posteriori}^ to which, by means of a short pedicle, 
is suspended a moveable and usually soft abdomen ; it is always fur- 
nished, under the anus, with from four to six closely approximated 
cylindrical or conical articidated mammillaj with fleshy extremities, 
which are perforated with numberless small orifices^ for the passage 
of silky filaments of extreme tenuity proceeding from internal reser- 
voirs. The legs, identical as to form, but of dilTerent sizes, are com- 
l)osed of seven joints, of which the two first form the hip, the third 
the thigh, the fourth § and fifth the tibia, and the two others the 
tarsus : the last is terminated by two hooks usually pectinated, and in 
several by one more, which is smaller and not dentated. The intes- 
tinal canal is straight, consisting of a first stomach composed of 
* From all the observations that have been made on the mode of copulation of the 
Araneides, I am still inclined to believe that these appendages are the genital organs. 
I have v.ainly sought for particular oi-gans on the base of the abdomen of a large male 
Mygale preserved in spirits. We are not always to judge from analogy; for the 
sexual organs in the female Glomeris, Julus, and other Chilognatha, are situated near 
the mouth, a fact of which no second example is to be found. 
The term ccphalo-/ horax would he more strict and proper ; not being in use, 
however, I have thought it best to avoid it ; neither will I employ that of corseUt, 
although generally admitted, because, with respect to the Coleoptcra, Orthoptera, 
&c., it only applies to the prothorax or first thoracic segment. 
I These holes are pierced in the last segment, which is frequently retracted. 
If it be strongly compressed, very small mammilloe, (at least in some species,) perfo- 
rated at the extremity, are protruded — they are the true fusi or spinning apparatus. 
Some naturalists think that the two smaller mammillae, situated in the middle of the 
four exterior ones, furnish no silk. 
§ This joint, or the first of the tibia, is a kind of patella. 
