800 Transactions.—Zoology. 
when finished looks like a thin film of isinglass, and is water-proof; and 
behind this film is the nest and egg-sac, which last is of various shapes and 
-= contains a large number of eggs. 
When the spider is disturbed it goes to the bottom of the pool, and if a 
small stick or straw is extended to it it at once gets ready for a fight, 
advancing its long and powerful mandibles for that purpose. The strength 
and formidable nature of these is well shown in the illustration which 
accompanies this paper, and for which I 
am indebted to Mr. A. Hamilton, who is 
also a member of the Society. 
When a small fish is placed in a bottle 
of water with one of these spiders, the 
latter will attack at once, driving its long 
sharp falces into the fish near the head and 
killing it instantly. Each spider seems to 
live in solitary state, and it is, I believe, an 
exceedingly pugnacious little animal; but I have not had the time or 
opportunity for studying its habits closely, and regret not being able to 
give more information respecting it. 
Each spider seems to be of two colours, the cephalo-thorax being a red- 
brown and the abdomen of a greenish hue, these colours becoming more 
distinct when the spider is placed in spirits. 
[Nore sy Dr. Hucror.—This spider is allied to the genus Argyronetra, 
of which 4. aquatica, the water-spider of Britain, is a well-known species. 
It differs from the generic characters given for that in the position of the 
ocelli, which are of equal size, eight in number, and arranged in divergent 
pairs. I can find no record of a species of water-spider inhabiting the sea, 
and, as Mr. Robson points out, it is difficult to conceive what can be its 
prey, unless it be insects that accidentally float on the surface. The water- 
spider builds its nest and hatches its young under water, constructing a 
diving-bell which it keeps supplied with air by bubbles entangled by the 
hairs which cover the abdomen and enclosed by the legs. For this species 
I propose the name Argyronetra marina.) 
PA X xpo quan x AE M Ee idu Ru E DELI ADM E M 
2e. ces 
