272 Transactions. — Zoology. 



least sign of life ; biit a slight pinch with the forceps makes 

 it either run smartly along tlie surface of the water or strenu- 

 ously struggle to dive. It, however, never succeeds in getting 

 more than its head and some of its legs under water. Like 

 Amaurobioides maritiina, Cambridge, and Doloiucdcs aquatic iis 

 and Lycosa ulifiinosa, Goyen, it is wholly unable to dive. To 

 get under water it must, like them, have some support for its 

 legs. It is able to run at a fair pace on the upper, but much 

 faster on the under surface of stones. This is no doubt owing 

 to the circumstance that its body, with the air entangled in its 

 pubescence, is of lower specific gravity than sea-water. On the 

 upper surface part of its energy is spent in holding its body down, 

 but on the under-surface most of it may be employed in running. 

 Owing to the fact that the stone must be turned a little to 

 expose the spider to view, I have been unable to determine 

 whether during immersion it seeks its prey or remains inactive. 

 It is difficult to believe that any land animal would adopt this 

 mode of existence merely for the sake of being under water 

 during a considerable portion of its life. On the stones under 

 which it lives there is abundance of animal life upon the juices 

 of which it might feed ; I incline, therefore, to the view that 

 it lives partly, if not entirely, upon the juices of marine ani- 

 mals, and that its preference for this kind of food has induced 

 it to take to sea-water. I have also found examples of this 

 spider in the crevices of the banks laved by the water at full- 

 tide, but, though I have searched diligently for it, have never 

 met with it at any greater distance from the sea. 



Its cocoon, wiaich is of a plano-convex shape, and attached 

 firmly by its plane surface to tlie under-side of stones, is also 

 under w^ater during a large portion of every day ; and the 

 young, as soon as they leave the cocoon, seem as nuich at 

 home in that element as the mother spider. The material of 

 the cocoon is of a thin leathery consistence, and apparently 

 impervious both to air and water. It contains about twenty 

 rather large pale- yellow, roundish eggs, which are placed in 

 tiers, and built into a rude sort of cone. They are loosely 

 agglutmated together, and attached to the central part of the 

 roof of the cocoon, which is invariably well inflated with air. 

 The young remain in the cocoon for some time after tliey are 

 hatched, and this imprisoned air is no doubt intended for their 

 use. Owing to its whitish colour, the cocoon is a rather con- 

 spicuous object ; but its fabricator is in colour so nmch like the 

 bits of wood and other material adhering to the stones that it 

 is difficult to distinguish it from them. It constructs neither 

 snare nor protective tube that I could discover. The air by 

 which its existence is supported during immersion is held 

 entangled in the dense pubescence of the abdominal ventral 

 siu'face. 



