24 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
Argyroneta has not been found in America, and no spider with habits 
in anywise resembling it, but our spider fauna contains a number of 
species, principally limited to the Citigrades, that are much at home either 
on or within the water. Several species of Dolomedes habitually 
Rafting Jive in the neighborhood of water, and may be seen continually 
eae running about upon the surface in search of prey. They avail 
"themselves sometimes of floating material in order to rest during 
their predatory excursions. This incidental occurrence, in the case of Dol- 
omedes fimbriatus of England, seems to have been specialized into the 
habit of constructing a rude sort of raft by lashing together floating leaves. 
This raft is utilized as a point of departure for raids upon water insects, 
and as a “lunch room” in which the captured prey are fed upon. It 
floats upon the fens of England, apparently at the sport of the wind. 
Dolomedes sexpunctatus, in the neighborhood of Philadelphia, is able 
to remain for a long time beneath the surface of water. I have on various 
occasions timed the period of submergence, and one specimen remained 
underneath the water forty-two minutes. While thus submerged the 
spiders are surrounded more or less completely with bubbles of air which 
have the appearance of a silvery coat of mail, as one looks down into the 
water. I have alluded elsewhere! to the habit of certain Lycosids, as re- 
ported by Dr. Alan Gentry, to live underneath frozen water during winter, 
and pass from point to point by means of threads strung upon water 
plants. This single observation opens up a new and strange chapter in 
the winter life and amphibious habit of these animals, which invites in- 
vestigation. No doubt the ability to exist while surrounded with water is 
of special value during periods of heavy rain, when their burrows 
Long must be inundated, and when they are themselves submerged for 
Pe ( haps d together. It is probably true that all 
ite, ours or perhaps days together. s probably true the 
spiders can endure a good deal of submerging; they seem at 
least to be able to survive under the heaviest and longest continued showers. 
How easily even Orbweavers can adapt themselves to the water habit may 
be found by reference to Vol. I, page 160, where it is seen that Tetrag- 
natha habitually sails over the surface of Deal Lake, New Jersey, by means 
of outspun filaments of thread; and where also (page 161) it is shown 
that Epeira can avail herself of an accidental float in the shape of her own 
flossy ball of cocooning silk. 
VI. 
Lycosa tigrina digs a tube in the earth from six to twelve inches in 
depth, which is bent in a little elbow near the surface. The upper part 
beyond the bend forms a sort of vestibule,? which assumes the shape of 
a broad, silk lined funnel at the mouth of the burrow. The background 
1 Acad. Nat. Sci., Philadelphia, 1884, page 140. 
2See Vol. L., Figs. 305, 306, page 323. 
