if@) NEW YORK STATE MUSEUM 
The young of many spiders develop from eggs neglected by the 
mother after deposition, but with the pisaurids the egg sac is not 
only protected but a web is spun for the use of the young until they 
have developed sufficiently to look after themselves. The females 
of Dolomedes spin the nursery web only when the young are begin- 
ning to emerge from the sac but Pisaurina mira fashions a 
retreat of leaves and silk, suspends herself with her sac to await 
development of the eggs, and expands the nursery by adding lines 
when the young emerge. Nothing is known of the breeding habits 
of Pelopatis and Thanatidius. 
Most of the species are found in the vicinity of water, hiding 
under stones or rubbish, stalking insects among the herbage along 
shore or running freely over the surface of ponds or slow streams. 
Some commonly take refuge beneath the surface when pursued and 
cling to submerged vegetation. Structural modifications such as a 
brush of soft hairs on the ventral surface of the terminal segments 
of the legs to permit surface navigation, and the hairy investment 
of the body for entangling air when submerged, have accompanied 
the adoption of the semi-aquatic habit. 
References to literature. The genera constituting the family 
Pisauridae were formerly distributed among other families, those of 
America chiefly in the Lycosidae but, in the case of Pelopatis and 
Thanatidius, in a separate group—the Podophthalmidae. Some 
references to the earlier literature are given below, and include 
accounts of American genera described under various families. 
Lycosoidae Thorell, On European Spiders, Upsala, 1860, pp. 188-105 
Lycosoidae Keyserling, Verh, K. K. Zool. Bot. Ges. Wien, 1876, 
26 :610-680, pls. 7-8 
Lycosidae Simon, Les Arachnides de France, 1876, 3:223-360; v. 4, 
1878, pls. 12-13 
Lycosidae Thorell, Synonyms of European Spiders, Upsala, 1870- 
1873, Pp. 271-355 
Lycosidae Emerton, Tran. Conn. Acad. 1885, 6:481-505, pls. 46-49 
— Includes Dolomedes, Ocyale etc., with typical Lycosidae. 
Lycosidae Marx, Proc. U. S. Nat. Mus., 1800, 12:560-566. Dolo- 
medes and Ocyale. 
Podophthalmidae Marx, Ibid, p. 567. Thanatidius dubius 
etc. 
Lycosidae Stone, Proc. Acad. Nat. Sci. Phila.. 18090, 42:420, pl. 15. 
fig. 8 
Lycosidae Banks, Can. Ent. 1892, 24:97 (Dolomedinae) 
Pisauridae Simon, Hist. Nat. des Araignées, 2d ed., 1808, 2:278-316, 
figs. 284-326 
Lycosidae Emerton, The Common Spiders of the U. S., Boston, 
1902, p. 67 
Lycosidae Montgomery, Proc. Acad. Nat. Sci. Phila., 1902, 54:534- 
592 
Pisauridae Comstock, A Classification of N. Amer. Spiders, Ithaca, 
1903, Pp. 50-51 
