120 Mr. Blackwall's Catalogue of Spiders 



gether, in a lenticular cocoon of dull green or yellowish-brown silk, of a com- 

 pact texture, measuring Jth of an inch in diameter, on quitting which the young 

 mount on the body of the mother. 



Like other species belonging to the same genus, Lycosa pallida, in construct- 

 ing its cocoon, slightly connects the margins of the two compact portions, be- 

 neath which the thin fabric of the zone is folded. This simple contrivance 

 affords an admirable provision for the development of the young in the foetal 

 state by an increase in the capacity of the cocoon consequent on the margins 

 of the compact parts becoming detached by means of the expansive force with- 

 in, the eventual liberation of the young being effected by the rupture of the 

 zone, which is the weakest part. This interesting fact in the economy of the 

 Lycosa appears to have escaped the observation of arachnologists. 



16. Lycosa piratica. 



Lycosa piratica. Walck. Hist. Nat. des Insect. Apt. t. i. p. 339. Hahn, Die 

 Arachn. b. i. p. 107. tab. xxvii. fig. 80. 



Lycosa piratica frequents marshes and the margins of pools in England and 

 Wales; it runs rapidly on the surface of water, even when encumbered with 

 its cocoon, and frequently takes refuge from danger beneath the surface of 

 that liquid, concealing itself among the leaves of aquatic plants, the air con- 

 fined by the circumambient water among the hairs with which it is clothed 

 enabling it to remain immersed for a considerable period of time. In June 

 the female deposits from 80 to 100 spherical eggs of a deep yellow colour, not 

 agglutinated together, in a globular cocoon of compact white silk, encircled 

 by a narrow zone of a slighter texture; it measures about |tb of an inch in 

 diameter, and the young, when extricated from it, climb upon the body of the 

 mother. 



Genus Dolomedes, Latr. 



17- Dolomedes fimbriatus. 



Dolomedes jimbriatus. Walck. Hist. Nat. des Insect. Apt. t. i. p. 345. Hahn, 



Die Arachn. b. i. p. 14. tab. iv. fig. 10. 

 Dolomedes Umbatus. Hahn, Die Arachn. b. i. p. 15. tab. iv. fig. 1 1. 

 Dolomedes marginatus. Hahn, Die Arachn. b. i. p. 15. tab. iv. fio-. 12. 



