222 IOWA ACADEMY OF SaEN'CE Vol. XXV. 191s 



Attidae.sayii : ''The relative length of the legs is very variable. 

 The fourth pair is usually the lon,uest, but often the first, and 

 even in some species the third pair. The legs of the first pair 

 are usually thickened, and often those of the second pair. Most 

 species can jump a considerable distance and this seems to be 

 done from all the legs at once and does, not depend oh their 

 relative length or size. The feet have two claws, generally long 

 and with many small teeth, aiul. under the claws, a bunch of long 

 hairs." 



Maliy of the spiders of this group are very brightly colored. 

 "As mUch so as are humming birds or beetles," says Peekham 

 in his "Attidae of North America." Unfortunately most of 

 thos,e in the collection at Ames have lost much of their bril- 

 liancy due to their early preservation in alcohol. The colora- 

 tion is due to a thick covering of hairs and irrideseent scales 

 which may easily be rubbed oW thus destroying some distinctive 

 characteristics. 



The males of this family, unlike those of many other families, 

 differ very little in size from the females. At mating time the- 

 males ndisplay a curious habit, one which perhaps makes the 

 study ;:of this group extremely interesting. At this time the 

 males- will dance before the female, and assume various attitudes 

 in order to display their ornaments to be-5t advantage. , It has 

 been observed in the genus Salticiis that two males will fre- 

 quently try to win the favor of the siame female. Each male be- 

 comes extremely jealous of the other, and waits for opportuni- 

 ties to attack his rival. The figlit between the two jealous lovers 

 lasts until oiu' of them is defeated when the other, minus most 

 of. his beautiful ornaments and bright scales becomes the yn-oud 

 possessor of his m^ate won by concpiest. 



, The following account of the feeding and nesting habits of the 

 Attida, has been taken from ''The Spider Book" by J. TT. Com- 

 stock : 



"The jumping spiders are hunters, pursuing their prey or 

 •springing upon it when it comes near them. They move side- 

 wise' or backward with great ease, and can jump a long distance. 

 They spin a drag line. I have seen them jump away from the 

 side of. a building, to catch an insect, Hying near, and (piickly 

 regain their position by means of the dragline. They make no 

 webs; except nests in wliicli tliey hide in winter or when moulting 

 or laying- eggs. These nests are sac-like in form, eoinpo.sed of 



