M. Koch was immature, the measurement of an adult female, discovered under a stone in a
wood at Oakland, on the 14th of August, 1855, is subjoined. Length, &ths of an inch;
length of the cephalo-thorax, ^th, breadth, ^th ; breadth of the abdomen, T4th ; length of a
posterior leg, ^ ths; length of a leg of the third pair, —ths. The length of M. Koch’s specimen
was only one line.
Theridion angulatum. PL XIV, fig. 133.
Theridion angulatum, Blackw., Lond. and Edinb. Phil. Mag., third series, vol. viii,
p. 483.
Blackw., Annals and Mag. of Nat. Hist., second series, vol. viii,
p. 445.
Length of the female, |th o f an in ch ; length of the cephalo-thorax, ^th, breadth, ^nd;
breadth of the abdomen, -jth; length of an anterior leg, 1th ; length of a leg of the third
pair, |th.
The abdomen, which is deeply notched in front, and projects over the base of the
cephalo-thorax, has an angular appearance, occasioned by two bold, lateral prominences,
situated on its upper part, nearer to the posterior than to the anterior extremity; the space
before the lateral prominences is of a deep, red-brown colour, the margins being the darkest,
and on each side of the medial line there are two minute, yellowish-white spots, forming a
long, narrow, quadrilateral figure; the posterior part has a pale, red-brown tint, and a transverse,
yellow line connects the lateral prominences, from which two obscure, angular bands
converge to the spinners; the whole o f the upper part has an irregular border of yellowish-
white, minutely freckled with red-brown; the sides and under part are of a dark, red-brown
colour, with streaks and small spots of a lighter shade; and the branchial opercula have a
yellow tint. The cephalo-thorax is convex, slightly hairy, compressed and prominent before,
rounded on the sides, and has an indentation in the medial line; its colour is pale, yellowish-
brown; on each side there is a longitudinal, red-brown band, another of the same hue
extends along the middle, and the margins have a yellowish-white tint. The eyes are seated
on black spots ; the four intermediate ones nearly form a square, the two anterior ones being
placed on a protuberance; those constituting each lateral pair are seated obliquely on a
tubercle, and are almost contiguous. The falces are moderately strong, conical, vertical, and
of a red-brown colour, with a spot of a darker hue near the base, in front. The maxillae are
enlarged where the palpi are inserted, obliquely truncated at the extremity, on the outer side,
and inclined towards the lip, which is nearly semicircular, being somewhat pointed at the
apex. These organs, with the palpi, which are short, and have a pectinated, curved claw at
their extremity, are of a red-brown hue. The sternum, which is oblong heart-shaped, has a
dark, red-brown tint. The legs are.of a yellowish-brown colour, with red-brown annuli; the
first pair is the longest, then the fourth, and the third pair is the shortest; the legs of the
second and third pairs are shorter, as compared with those of the first and fourth pairs, than
is customary with the spiders of this genus; each tarsus is terminated by three claws; the two
superior ones are curved and pectinated, and the inferior one is inflected near its insertion.
The male is smaller and darker coloured than the female; its legs, which are slender,
are longer than hers, and its abdomen is without lateral protuberances on the upper part.
The humeral joint of its palpi is long; the cubital and radial joints are short, the latter being
the stronger; and the digital joint, which has an oblong-oval form and red-brown hue, is
convex and hairy externally, concave within, comprising the palpal organs; these organs are
highly developed, vascular, complicated in structure, with a black spine curved from the
outer to the inner side, round their base, several curved, pointed, black processes at their
extremity, extending a little beyond the end of the joint, and are of a pale, brownish-red
colour.
A specimen of this remarkable species was detected in a cleft of a rail at Oakland, in
April, 1835. It was a female, and, like Tetragnatha externa, frequently extended the first and
second pairs of legs forwards, and the fourth pair backwards, in a line with the body.
In the summer of 1860, the Rev. O. P. Cambridge took both sexes of Theridion angulatum,
in a state of maturity, at Hursley, near Winchester. The female was much paler, as may be
seen by inspecting the figure, than the one described above, vjhich was immature, but there
is no reason for doubting their specific identity. This spider has various striking characteristics
in common with the JUpisifius truncatus of Walckenaer (‘ Hist. Nat. des Insect. Apt.,
tom. ii, p. 375, pi. 21, fig. 1 d ; and tom. iv, p. 515), but there does not appear to be any
necessity for removing it from the genus Theridion.
Theridion variegatum. PI. XIV, fig. 134.
Theridion variegatum, Walck., Hist. Nat. des Insect. Apt., tom. ii, p. 332.
___ ___ B l a c k w ., Annals and Mag. of Nat. Hist., second series, vol. viii,
p. 446.
— thoracicum, Wider, Museum Senckenb., Band i, p. 218, taf. 14, fig. 11.
— callens, Blackw., Linn. Trans., vol. xviii, p. 627.
Ero variegata, Koch, Uebers. des Arachn. Syst., erstes Heft, p. 8.
Length of the female, §th of an in ch ; length of the cephalo-thorax, ^th, breadth, ^ th ;
breadth of the abdomen, ^th; length of an anterior leg, ?th; length of a leg of the third
pair, ?th.
The cephalo-thorax is oval, glossy, and very convex, but it slopes abruptly in the
posterior region, where there is an indentation in the medial lin e ; a row of fine, curved
bristles, which are directed forwards, extends along the middle, and its colour is pale,
yellowish-brown, the lateral margins, a triangular spot in the centre, which projects a line
from the middle of its base to the eyes, and has a narrow triangle at its apex, whose base
terminates at the medial indentation, together with a small triangular spot immediately behind
each lateral pair of eyes, being black. The eyes are seated on black spots; the four intermediate
ones form a square, the two anterior ones being placed on a protuberance, and the