113 



Variation Notes. 



0. H. ElGENMANN AND CLARENCE KENNEDY. 



The Spinning of the Egg-Sac in Lycosa. 

 W. J. Moenkhaus. 



The habit of the female spinning a round, ball-like egg-sac and 

 carxying this suspended from the spinners during the period of incuba- 

 tion, is, so far as I can determine, characteristic of the entire family of 

 ground spiders, the Lycosldae, with the exception of the single genus 

 Dolomedes. The process of the construction of the cocoon has been sel- 

 dom observed, so far as I can determine from the literature. This is due 

 to the difficulty attending such observation, since all of the species either 

 tunnel more or less deeply into the ground or live in retreats under stones, 

 boards, and the like. I had tried for a long time, without satisfactory 

 results, to observe this until I finally hit upon a species Lycosa sp. that 

 permitted me to make the observation very completely. The plan had been 

 to place gravid females in glass jars half-filled with earth, and by moisten- 

 ing this next to the glass induce her to construct her burrow there and 

 thus enable me to watch her actions through the glass. While I got 

 several females thus to construct their bm-rows and spin their egg-sacs, 

 I was not able to see sufficiently well through the glass, which always 

 became pretty well besmeared with earth during the excavation. In the 

 case under consideration, howeA^er, the whole process occurred above 

 ground, so that I could see it step by step. This, briefly, ran as follows: 



She first excavated a shallow hole in the middle of the jar about one- 

 third greater in diameter than the length of her body. Tbis she did with 

 her mandibles and palpi, piling the excavated ground iu a crescentic heap 

 around one side of the hole. Then she spun a thin sheet over the hole, 

 extending from the top of the crescentic heap to the opposite side, com- 

 pletely covering the hole. This sheet, thus, was not horizontal, but in- 

 clined, and in the instance observed about 25 degrees, the inclination, of 

 course, being determined by the height of the crescentic embankment. 

 Upon the center of this sheet a crescent-shaped pocket was constructed 

 with the broad and open side directed toward the higher end of the incline. 

 Into this the eggs were deposited immediately after its completion. The 



