138 DRASSIDiE. 
base upwards, and are of a dark, reddish-browm colour, the central and most prominent part 
having a pale, reddish-brown tint. 
Argyroneta aquatica habitually passes the greater part of its life in the wmter, not only 
pursuing its prey in that liquid, but constructing beneath its surface a dome-shaped cell, in 
which is placed its cocoon of white silk, of a compact texture and lenticular form, containing 
from eighty to a hundred spherical eggs, of a yellow colour, not agglutinated together. This 
Cell is supported in a vertical position, the open part being directed downwards, by lines of 
silk connecting it with aquatic plants, and as it comprises a considerable quantity of atmo¬ 
spheric air, the spider can at all times occupy it without experiencing the least inconvenience. 
In swimming and diving Argyrondci ciquatica assumes an inverted position, and is more or less 
enveloped in air confined by the circumambient water among the hairs with which it is 
clothed, the supply being always more abundant on the under than on the upper part, in con¬ 
sequence of the greater length and density of the hairs distributed over its surface. 
This species is found in pools and ditches in various parts of England. It is of frequent 
occurrence in the fens of Cambridgeshire, from which locality a pair was transported to 
Crumpsall Hall, near Manchester, in the summer of 1833; each individual was inclosed in a 
small, tin box, and neither of them appeared to suffer materially from the confinement. After 
a lapse of ten days, during which period they were without w'ater, these spiders were conveyed 
to Oakland, in Denbighshire, where they arrived in perfect health. One of them, on being 
placed in a large goblet more than half filled with water, speedily formed a dome-shaped cell 
beneath the surface, attaching it to the side of the glass by means of numerous silken lines, 
and being well supplied with insects, it lived in this state of captivity till the commencement 
of winter, when, on the temperature of the room in which it was kept becoming much 
reduced, it entered the cell and remained there in a state of torpidity, with its head down¬ 
wards. A gentleman on a visit at the house, whose curiosity to examine the spider minutely 
in its hybernaculum was greater than his prudence, inclined the glass so much that the air 
escaped from the cell, the water flowed in, and before information of the circumstance was 
given, the dormant inmate had perished. 
The aquatic habits of this species have induced M. Walckenaer to constitute wfith it a 
distinct family; but upon the same principle, Lycosa piratica and Dolomedes fimbriatus might 
be separated from the Lycosida, as they descend spontaneously into water and perform the 
function of respiration in that situation precisely in the same manner as Argyroneta aquatica 
does; yet the position, which in conformity with their organization they so consistently occupy 
in the systematic arrangement of the Araneidea, has not been disturbed. Regard being had 
to these considerations and to the relations of affinity predominant in the structure and 
economy of Argyroneta aquatica , it has been deemed expedient to transfer it to the family 
Drassidcc. 
Mr. R. Templeton states that Argyroneta aquatica abounds in the neighbourhood of 
Lurgan, in Ireland. 
