226 The Ohio Journal of Science [Vol. XX, No. 7, 



instant death. This fact, it seems, is the reason why most 

 spiders that attack insects by jumping upon them will seldom 

 ever attack an insect with a strongly chitinized body but will 

 attack a large insect with soft body coverings. 



I have often seen Phidippus andax pursuing other spiders 

 and occasionally have seen them eating small spiders such as, 

 Xysticus gidosus and Philodromus vulgaris. But they are often 

 the victim themselves. When one of these spiders jumps or 

 falls into the web of Argiope riparia or Argiope trifasciata it 

 is helpless and late in the fall many of them become the prey 

 of these spiders. 



Another incident shows that this spider possesses something 

 which borders upon intelligence. One morning I was watching 

 one near a large stump. He jumped around evidently in search 

 of prey for sometime. Presently he spied a small spider, 

 Castiafteira descripta running about and began to pursue it. 

 Castianeira descripta was too swift for him and he soon gave 

 up the chase. Next he jumped upon a Funnel Weaver's web, 

 Agelena ncevia, and began searching it. The Funnel Weaver 

 soon came from its hiding place and chased Phidippus off the 

 web. Soon he spied a grasshopper which was crossing a small 

 stick which was lying on top of two larger sticks. 



The two larger sticks formed the base and hypotenuse of 

 a triangle. The stick forming the base was a very large limb. 

 Phidippus peeped up over the edge of this piece and saw the 

 grasshopper with its head pointed in his direction. He imme- 

 diately ran down the under side of the large limb to where the 

 two large limbs came to a point and ran back up the smaller to 

 the rear of the grasshopper. When he had stolen up to within a 

 •couple of inches of the grasshopper he made a leap and landed 

 •on the grasshopper's back. 



Phidippus audax was watched to see what insects were 

 eaten both under natural conditions and in captivity. In the 

 iield I have found them eating: Tabanidae, Blattidse, Ves- 

 pidae, Capsidas, Acridid^, Gryllidae. 



Tests were made to see how many insects of the same 

 species this spider would eat in one week, one test on Lygus 

 pratensis was as follows: Oct. 17, Oct. 18, Oct. 19*, Oct. 20*, 

 Oct. 21, 3*; Oct. 22*, Oct. 23, 4*; Oct. 24, 2. 



"Indicates insect was placed in the cage, but was not eaten. 



