136 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
Genus EPEIRA WaAtcKkEnArrR, 
Tue original genus Epeira of Walckenaer has been divided and subdivided at various 
times, yet still contains by far the greatest number of orbweaving species, not only in the 
United States, but other parts of the world. That it must further be subdivided is apparent 
to any one who has given much attention to the species which are grouped thereunder; 
but equally plain that it will be difficult to distinguish sharply the characteristics upon 
which good generic differences may be based. The following are the principal character- 
istics herein held to mark the typical Epeira.* 
The cephalothorax is moderately high and oval, more or less shortened or cordate 
the corselet for the most part being well rounded. It is moderately high, the fosse placed 
near the centre of the summit, from whence the corselet slopes more or less sharply to the 
base, which is truncated and often indented. The corselet grooves are sufficiently distinct ; 
the cephalic suture well marked. The margin of the corselet is often a narrow belt free 
from pubescence more or less shelving to the articulation with the legs. The head is lowly 
arched, somewhat depressed at the face, which is wide, though narrower than the corselet, 
and somewhat quadrate. The sternum is shield shape or cordate, somewhat longer than 
wide; the labium longer than wide, strong, half as high as the maxilla, which are as 
wide, or nearly as wide, as long. 
The eyes are placed in three groups, of which the side eyes are upon tubercles or 
elevated bases, the four middle eyes upon a rounded eminence, the ocular quad being in the 
form of a quadrilateral whose greatest width nearly equals the length. The front side of 
the quad is usually a little wider than the rear. The space between the sidefront and 
midfront eyes is equal to 1.5 times the area of the latter, or from 2 to 2.5 the intervening 
space thereof. The space between the siderear and the midrear eyes is uSually greater than 
the above. The clypeus is low, rarely exceeding 2 to 2.5 times the diameter of the midfront 
eyes. The eye rows are not widely separated at their greatest point of divergence and 
closely approximate at the sides; the front row is slightly recurved, the rear row slightly 
procurved. 
The legs are in order of length 1, 2, 4, 3; stout in all the joints; the tarsus and meta- 
tarsus gradually diminishing in size, and not noticeably thinner than the other joints. 
They are clothed heavily with hairs and bristles, and abundantly with strong spines. The 
palps in the female are armed as the legs; the digital joint with a strong claw; longer 
than the radial joint; the cubital joint being about half the length of the latter, and the 
humeral joint approximating the length of the digital, but usually longer. The abdomen 
is usually subglobose or oval, rounded at the base and diminished at the apex, or is a 
triangular ovate. The spinnerets are distal and the base overhangs the cephalothorax 
sometimes for half its length. The skin is soft and pubescent. The epigynum has generally 
a prolonged scapus. 
The male in general form and markings resembles the female. Tibia-II is frequently 
widened at the tip, and in some species provided with strong denticulate clasping spines. 
’ The coxze are often marked by spurs at the articulation with the trochanter, or upon the 
base. He is commonly much smaller than the female, but sometimes nearly equals her 
in size. 
It will probably be observed in the following descriptions that the above specifications 
of the typical Epeira are not strictly adhered to, and in some points indeed are widely 
divergent therefrom. But a strong indisposition to multiply new genera, together with the 
confusingly interblended characteristics above referred to, have prompted to, if not justified 
‘such a course. No doubt future students, who may have a greater amount of material in 
hand, will be able not only to indicate necessary divisions, but to unite some of the genera 
already created from this overflowing group. 
* For the technical terms used in description of species see Chapter VI., page 124 sq. 
