188 Transactions.—Zoology. 
In some of the Araneidea the spiracular plates are four in number (f. 15m, n), 
but for the most part there are only two ; where more than two are present it 
has been found that the posterior pair are connected with trachec, the anterior 
ones with pulmo-branchie. In some few spiders a kind of supernumerary 
spiracular slit or opening is visible, near to the ordinary one, but not always 
similarly placed. Cambridgea quadrifasciata, L. Koch, as described below, is 
an instance of this, where, when the spider is looked at in profile (f. 3p), it is 
above the ordinary one on each side (see also post, description of Plate VL, f. 2и). 
The Falces, two in number (f. 5d, 16d, 32), are one-jointed, and articulated 
beneath the fore part of the cephalo-thorax; they are generally armed, more or 
less, with teeth on their inner sides, and each terminates with a moveable curved 
fang, which, when not in use, is folded down either across the inner side of the 
extremity of the falx, as with most spiders (f. 5d), or backwards along its 
length as in one family—Theraphosides (f. 157); by means of these fangs a 
poison secreted within the caput is instilled into the wound made by them, 
proving, no doubt, fatal to the spider's prey, and often nearly so—in the 
genus Lathrodectus—to human beings; for instance, Lathrodectus katipo, 
Ll. Powell, vide Trans. N.Z. Inst., III., pp. 56-59; also, F. W. Wright, id., IL, 
pp. 81-84; and W. L. Buller, id., IIL, pp. 29—34. 
The Zyes (f. 19, 19)—as at present known—are two, four, six, or eight in 
number, but by far the larger proportion have eight eyes; two known species 
alone have four—Miagrammopes, Cambr., and Tetrablemma, id.—and only one 
species—JNops, Macleay—has yet been described with two ; the eyes are 
variously disposed, but always symmetrically on the fore part of the caput— 
1.е., the cephalic segment— which is generally well defined by an oblique 
indentation and constriction on either side of the anterior part of the cephalo- 
thorax (Ё 37, 45, and 164). The number and general position of the eyes form 
one valuable character for the formation of genera, while their relative size is 
strongly specific. 
The Legs, eight in number, are articulated to а kind of separate plate 
(sternum, f. 27; and 157), which forms the underside of the cephalo-thorax ; 
in one genus (Miagrammopes, Cambr.) from Ceylon, no sternum, properly so 
called, exists, the legs being articulated to the continuous underside of the 
cephalo-thorax. 
Except in one or two species the legs are seven-jointed, and variously 
furnished with hairs, bristles, and spines, each tarsus ending with two or three 
claws, generally more or less bent or curved, and commonly pectinated, or 
finely denticulate ; these claws are used as hooks, to give a tension to the lines 
of their snares by holding on and straining upon them. The spines and 
bristles also are, in many cases, used in the construction of the silken snares, 
in which spiders entrap their prey ; and the males of some species have a 
