Genus ERGATIS (jBlacbodU).
Byes nearly equal in size, disposed on the anterior part of the cephSio-thorax in two
transverse rows ; the intermediate ones of both rows form a square, and those of each lateral
pair are placed obliquely on a tubercle near to each other.
Maxilla convex at the base, somewhat dilated near the middle, rounded at the extremity,
which is more abruptly curved on the inner than on the outer side, and inclined towards the
lip.
l i p large, triangular, acute, or rounded at the apex. ,
le y s rather short; the first pair is the longest, then the second, and the third pair is the
shortest.
Ergatis benigna. PI. IX, fig. 93.
Ergatis benigna, Blackw., Linn. Trans., vol. xviii, p. 608.
— Blackw., Annals and Mag. of Nat. Hist., second series, vol. viii>
p .9 9 .
Theridion benignwm, Walck., Hist. Nat. des Insect. Apt., tom. ii, p. 837.
— -----Sund., Vet. Acad. Handl., 1831, p. 122.
Bictyna benigna, Sund., Consp. Arachn., p. ] 6.
— Koch, Die Arachn., Band iii, p. 27, tab. 83, figs. 184, 1851
— — Koch, Uebers. des Arachn. Syst., erstes Heft, p. 12.
Clubixma parvula, Blackw., Loud. and Edinb. Phil. Mag., third series, vol. iii, p. 487,
Drassus parmlus, Blackw., Research, in Zool., p. 387.
Titulus J 5, Lister, Hist. Animal. Angl., He Aran., p. 55.
Length of the female, :ths of an in ch ; length of the cephalo-thorax, ;,th, breadth, '.til;
breadth of the abdomen, / t h ; length of an anterior leg, )th; length of a lég of thé
third pair, |th.
The cephalo-thorax is compressed before, very convex in the cephalic region, hut
depressed and rounded in fron t; the sides and posterior part are depressed, the former being
marked with farrows, which converge towards the middle ; it is of a very dark-brown colour,
with five lines of white hairs on the anterior convexity, which unite at their extremities; the
space below the eyes and the base of the falces are also supplied with white hairs. The
falces are powerful, conical, vertical, and armed with a few teeth on the inner surface; the
maxillae are strong, and inclined towards the lip, which is rounded at the apex; the sternum
is heart-shaped. These parts are of a very dark-brown colour, the sternum being thinly
covered with whitish hairs. The legs and palpi are robust, and of a brown hue; the two
superior tarsal claws are curved and pectinated, and the inferior one, is, inflected near its base.
The abdomen is oviform, clothed with short hairs, convex above, projecting over the base of
the cephalo-thorax; along the middle of the upper part a broad, dentated, dark-brown band
extends, which is generally Bisected by an irregular, transverse, white line, between which
and the spinners there is a series of obscure, angular lines, o f a pale-brown or whitish colour,
whose vertices are directed forwards; a deep border, of a dull-white hue, which becomes
narrower' as” it' approaches the spinners, encompasses the dark-brown Band"; the siSes are of
a dark-brown colour, mottled with white; the under part has a dull-white hue, a broad, dark-
brown band, marked with a few. white , spots, occupying the medial line; and the colour of
the branchial opercula is brown.
The male is smaller and darker coloured than the female, and its falces, which are
longer, have a large prominence on the under side, and a minute onë in front, near their
articulation; they are hollowed about,the middle of the inner surface, leaving a strong
prominence near the extremity, on the lower part of which a few small teeth are situated’;
* little forwards at the end. The cubital and radial joints of the palpi
are short; the former is the stronger, and the latter has a small, pointed process projecting
at right angles from the upper part, in front, and an obtuse apophysis at its extremity, on
the outer sid e; the digital joint is oval, convex and hairy externally, concave within, comprising
the palpal organs; they are highly developed, have a strong, corneous process
curving from below upwards, and terminating in a spiral point, which extends nearly to the
articulation o f the radial with the cubital joint, and are o f a reddish-brown colour.
vari°us plkees which arachnologists have assigned to the spiders constituting the
genus Ergatis, in their attempts to arrange the Araneidea in accordance with the natural
relations of affinity and analogy, afford a sufficient indication that the task of determining
their true position, before the discovery o f those marked characters which serve to connect
them with the dniflonida, was attended by no ordinary difficulties. M. Walekehaer, in his
Hist. Nat. des. Insect. A p t./ t. iv, p. 500), has formed, with the species belonging to the
genus Ergatis, previously included by him in the genera Brassrn and Theridiim, a small group
which he has placed at the head of his genus Argus; but so closely are they allied to the
Cinifiones by their structure and functions, being provided with eight spinners and calamislra,
employed in the construction of their snares, that they cannot be removed from the family
Ciniflonida, which is founded upon those characters, without doing violence to the recognised
principles of classification.
Ergatis benigna fabricates an irregular web of whitish silk at the extremity of the twigs
o f Èeath a n i gorse growing in various parts o f England^ Wales, and Scotland. It pairs in
May, and in that and the succeeding month the female constructs two Or three contiguous,
lenticular, white cocoons, o f a compact texture, measuring about one seventh of an inch in
diameter, on an average, which she attaches to the stems surrounded by her web, enveloping
them with the refuse of her prey. Each cocoon contains from ten to thirty spherical eggs,
of a pale-yellow colour, which do not adhere together.