AGELENA N^VIA Walckenar 



Material. Agelena naevia is the " common grass-spider" 

 and may be collected in great quantities during July and August. 

 Specimens should be preserved in 70% alcohol. Stronger alcohol 

 is injurious, formalin ruins the specimens completely. Fer- 

 tilized females will deposit eggs in a cocoon in confinement. The 

 spiderlings should be fixed in my sublimate mixture. Every 

 student should receive a mature female, a mature male, an im- 

 mature specimen, a series of prepared slides with transverse sec- 

 tions through a spiderling and a prepared slide with median 

 longitudinal section. 



Descriptive Part 



Agelena naevia is a very common spider inhabiting the United 

 States. It belongs to the Order Araneae, Class Arachnida, of 

 which it is a typical representative. Meadows are often covered 

 with the webs of Agelena, which glisten like silver in the morning 

 dew of autumn. They have the shape of a broad sheet extending 

 into a long funnel in the depth of which the spider hides waiting 

 for its prey. 



External features and segmentation. The body of 

 Agelena shows a clear separation into an anterior portion or 

 cephalothorax and a posterior portion or abdomen. The latter is 

 joined to the cephalothorax by a very thin stalk or pedicel. With 

 the loss of external and to some extent even of the internal seg- 

 mentation, the differentiation of the integument into sclerites 

 has been also considerably impaired, if not completely oblit- 

 erated. The tergites of the cephalothorax are fused together, 

 forming a single shield or carapace. A cephalic groove with sulci 



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