32 LŸCOSIDÆ.
Like other species belonging to the same genus, Lycosafluviatilis, in constructing its cocoon,
slightly connects the margins of the two compact portions beneath which the thin fabric of
the zone is folded. This simple contrivance affords ' an admirable provision for the development
of the young in the foetal state by an increase in the capacity of the cocoon consequent
on the margins of the compact parts becoming detached by means of th e , expansive force
within, the eventual liberation of the young being effected by the rupture of the zone, which
is the weakest part. This interesting fact'in the economy of thz Lycosa appears to have
escaped the observation of arachnologists.
The specific name arenaria, given by M. Koch to this Lycosa, having been previously
conferred on another species of the genus by M. Savigny, the trivial namejluviatilis is here
substituted for it. M. Walckenaer has regarded this species as a variety of Lycosa vorax
Hist: Nat. des Insect. Apt.,' t. i, pp. 313^314, and t. iv, p. 392), from which it differs in
size,'in the design formed by the distribution of its colours, and in its habits.
Lycosa cambrica. PI. II, fig- 14.
Lycosa cambrica, Blackw., Linn. Trans., vol. xviii, p. 614.
__ -hivoit Blackw., Annals and Mag. ‘ of Nat. Hist., second series, vol. vii,
p. 396.
Length of the female, Jths of an inch ; length of the cephalo-thorax, ^ths ; breadth, ®ths ;
breadth of the abdomen, ith ; length of a posterior leg, Jiths|flength of a leg of the third
pair, fths.
The intermediate eyes of the anterior row are rather smaller than the lateral ones. The
cephalo-thorax is large, glossy, and of a brownish-black hue ; but it is clothed with yellowish-
brown hairs, which are densest on the anterior part, and the sides and posterior part are
marked with white hairs disposed in irregular spots. The falces are powerful, conical, with
a few teeth and a fringe of long hairs on the inner surface ; the maxillae are strong, curved
towards the lip, and are obliquely truncated and fringed with hairs at the extremity, on the
inner side; the sternum is heart-shaped. The colour of these parts is brownish-black, the
maxillae having a tinge of red at the extremity, and the sternum being thinly covered with
long black, and short, yellowish-brown hairs. The legs and palpi are of a dark, yellowish-
brown hue, marked with black annuli. The abdomen is rather broader at the posterior than
at the anterior extremity, densely covered with hairs, convex above, projecting oyer the base
of the cephalo-thorax ; the colour of the upper part is yellowish-brown, a band of a paler hue
extending from the anterior part, along the middle, more than a third of its length ; this band
has an obscure border of black, on which there are several irregular white spots ; a series of
black and white spots, disposed alternately, commences near the posterior extremity of the
band, on each side of the medial line, and extends to the spinners, where the two meet; the
black spots of both series are connected by obscure, black, angular lines, each comprising a
white spot within its vertex; the sides are mottled with dull olive-brown, yellowish-
brown, and white; and the under part has a yellowish-brown tin t; the sexual organs, which
have a longitudinal septum in the middle, are of a red-brown colour; and that of the spinners
is dark-brown.
The male is smaller and paler than the female; but it resembles her in the general
distribution of its colours. The base of the thigh of each anterior leg is black. The axillary
and humeral joints of the palpi have a dark-brown h u e ; the colour of the cubital and radial
joints, which are short, is yellowish-brown; and the digital joint has a dark, reddish-brown
tint. ■ This last joint is of a slender, elongated, oval form, convex and hairy externally, and
concave underneath, near the base; this concavity comprises the palpal organs, which are
slightly developed, and of a dark, reddish-brown colour.
Adult males and females of this handsome spider were taken on swampy ground in
woods at Oakland, near Llanrwst, in May, 183$. The decidedly curved form of the maxillae,
an approximation to which may be observed in Lycosa campestris, Lycosa allodroma, and some
other species, has not been considered of sufficient importance to require its separation from
the genus Lycosa, with the semi-aquatic species of which genus it is very closely allied by its
general organization, habits, and colours.
In July and August, the female deposits between sixty and seventy spherical eggs of a
yellow colour, in a globular cocoon of compact, white silk, which is encircled by a narrow zone
of a slighter texture, and measures one fifth of an inch in diameter.
A deficiency of the right intermediate eye of the anterior row has been observed in an
adult male of this spider.
M. Walckenaer is certainly mistaken in supposing that Lycosa cambrica is identical with
Lycosa allodroma (‘Hist. Nat. des Insect. Ap t./tom . iv, p. 395), for it is not only much
smaller than that species, but its colours, which are dissimilar, constitute by their arrangement
a different design both on the cephalo-thorax and abdomen ; there is some diversity also
in the structure of its palpal organs, and in the relative size of the four minute eyes forming
the transverse frontal row.
Lycosa latitans. PI. II, fig. 15.
Lycosa latitans, Blackw., Linn. Trans., vol. xviii, p. 612.
— — Blackw., Annals and Mag. of Nat. Hist., second series, vol. vii, p. 397.
— (Potamia) palustris, Koch, Die Arachn., Band xv, p. 4, tab. 505, figs. 1415 and
1416.
, Length of the female, |th of an inch ; length of the cephalo-thorax, ^th, breadth, ^th ;
breadth of the abdomen, ^th ; length of a posterior leg, ^ths ; length of a leg of the third
pair, ith.