132 PROCEEDINGS OF THE ACADEMY OF [1883. 



forming the foundation of its watcli-tower of little quartz pebbles, 

 sometimes producing a structure of considerable beaut}'. In this 

 sandy site, the tube is preserved intact by a delicate secretion of 

 silk, to which the particles of sand adhere. This secretion scarcely 

 presents the character of a web-lining, but has sutficient consis- 

 tency to hold aloft a frail cylinder of sand and silk, when the sand 

 is carefully scooped away from the site of the nest. 



A nest recentl}^ obtained from Vineland, N. J., fui-nished an 

 intei'esting illustration of the power of these araneads to intelli- 

 gently adapt themselves to varying surroundings arid to take 

 advantage of circumstances with which they certainly could not 

 have been previously familiar. In order to preserve the nest, with 

 a view to studj^ the life-history of its occupant, the sod containing 

 the tube had been carefully dug up and the upper and lower 

 openings plugged with cotton. Upon the arrival of the nest in 

 Philadelphia, the plug guarding the entrance had been removed, 

 but the other had been forgotten and allowed to remain. The 

 spider, which still inhabited the tube, immediately began removing 

 the cotton at the lower portion, and cast some of it out. But 

 guided apparently by its sense of touch to the knowledge that 

 the soft fibres of the cotton would be an excellent material with 

 which to line its tube, she speedily began putting it to that use, 

 and had soon spread a soft, smooth la^^er over the inner surface 

 and around the opening. The nest, in this condition, was exhib- 

 ited and showed the interior to be padded for about four inches 

 from the summit of the tower. Dr. McCook pointed out the very 

 manifest inference that the spider must for the first time have 

 come in contact with such a material as cotton, and had imme- 

 diately^ utilized its new experience by substituting the soft fibre 

 for the ordinary silken lining ; or, rather, adding it thereto. This 

 nest with the cotton wadding is figured on p. 131. 



June 26. 



Dr. W. S. W. RuscHENBERGER, in the chair. 



Twenty-three persons present. 



The Fishes of the Batsto Biver, N. J. — Prof. Cope gave an 

 account of the results of fishing in the confined waters of a broken 

 dam on the Batsto River, New Jersey. The species obtained 

 were the following. Percidje : Pcecilichthys erochi^ous Cope; En- 

 neacanthus simulans Cope ; Mesogonistius chsetodon Baird ; Apho- 

 doderidse : Aphododerus sayanus Gill.; Umbridfe : Umbra limi 

 Kirtl. ; Esocidai : Esox ttmbrosus Kirt. ; Esox reticulahis Les. ; 

 Cyprinidfe : Gliola chalyhsea Cope ; Catostomida? : Erimyzon 

 sucetta Lac; Siluridie : Amiurus prosthistius Cope, sp. nov. ; 

 Anguillidje : Anguilla rostrata Les. Prof. Cope remarked that 

 these fishes represent the fish fauna of the Carolinian district of 



