EPEIRA. 
331 
their distribution are liable to vary, yet they may always be distinguished, when adult, 
by permanent, organic characters, and particularly by differences in the structure of 
the organs of generation in both sexes of each species, as explained in the foregoing 
descriptions. 
Epeira scaiaris. PI. XXIV, fig. 240. 
Epeira scalaris, Walck., Hist. Nat. des Insect. Apt., tom. ii, p. 46. 
— — Halm, Die Arachn., Band ii, p. 27, tab. 47, fig. 114. 
*— — Blackw., Lmn. Trans., vol. xix, p. 127. 
_ — Blackw., Annals and Mag. of Nat. Hist., second series, vol. ix, p. 471. 
— pyramidata, Sund., Yet. Acad. Handl., 1832, p. 242. 
— —. Koch, Uebers des Arachn. Syst., erstes Heft., p. 2. 
— — Koch, Die Arachn., Band xi, p. 107, tab. 384, fig. 912. 
Length of the female, ^ths of an inch; length of the cephalo-thorax, -^ths, breadth, ^ths ; 
breadth of the abdomen, T 3 B ths; length of an anterior leg, §ths; length, of a leg of the third 
pair, fths. 
The abdomen is large, oviform, thinly clothed with hairs, convex above, and projects 
greatly over the base of the cephalo-thorax; the upper part is of a pale-yellow colour, with a 
small, circular, brownish-black indentation on each side of the anterior region, from which a 
streak of the same hue passes obliquely outwards ; on the posterior part there is a large, 
brownish-black, pyramidal mark, with sinuous lateral margins, whose apex extends to the 
spinners; the sides and under part have a brownish-black hue ; the former are mottled with 
yellowish-brown, and the latter has a curved, yellow mark on each side of the medial line ; 
the sexual organs are prominent, glossy, and of a reddish-brown colour ; a curved, taper, 
wrinkled, membranous process, connected with their anterior margin, and directed back¬ 
wards, has a yellowish-brown tint, and that of the branchial opercula is yellow. The cephalo- 
thorax is glossy, compressed before, truncated in front, rounded on the sides, moderately 
convex, and has a large indentation in the medial line; it is sparingly clothed with fine, hoary 
hairs, and is of a pale, dull-yellow colour, with a broad, longitudinal, blackish band on each 
side, and a narrower one of the same hue extending along the middle. The four intermediate 
eyes, which are seated on a prominence, nearly form a square, the two anterior ones being 
rather wider apart than those of the posterior pair; the eyes of each lateral pair are placed 
obliquely on a tubercle, and are nearly contiguous. The falces are powerful, conical, vertical, 
armed with teeth on the inner surface, and of a yellowish-brown colour, with the exception 
of their extremity, which has a brown tint. The maxillae are short, strong, and rounded at 
the extremity; the lip is semicircular, but slightly pointed at the apex ; and the sternum, 
which is heart-shaped, has eminences on the sides, opposite to the legs. These parts are of a 
brownish-black hue, the extremities of the maxillae and lip having a yellowish-brown tint. 
The legs are robust, provided with hairs and numerous erect spines, and of a pale, yellowish- 
brown colour, with dark-brown annuli; the tarsi are terminated by three claws of the usual 
