Superfamily Argiopoidea 



species have been described from the United States, of which 

 the following is the most common: 



Crustulina guttata (C. gut-ta'ta). — There are two varieties 

 of this species differing in the colouring of the abdomen; but these 

 varieties intergrade. In both the cephalothorax is dark brown; in 

 one the abdomen is bright yellow or orange without markings; in 

 the other the abdomen is brown and marked on the dorsal aspect 

 with a median band on the basal part, a curved line around the an- 

 terior part, and four spaces about the four muscle impressions of 

 a paler colour; and with several silvery white spots, usually two on 

 each side and one or two in the middle line. The body is about 

 one twelfth inch in length. This spider is common under stones 

 at all seasons. 



Genus STEATODA (Ste-a-to'da) 



This is one of several genera of comb-footed spiders in which 

 the sternum is pointed behind; it can be distinguished from the 

 others that occur in our fauna by the fact that the anterior median 

 eyes are much larger than the anterior lateral eyes. It is repre- 

 sented in the United States 

 by the following common, 

 and widely distributed spe- 

 cies: two others are found 

 in the Far West, and one in 

 Canada. 



Steatoda boreal is (S. 

 bor-e-a'lis). — This is a 

 dark reddish brown spider 

 measuring when full grown 

 about one fifth inch in 

 length. The cephalothorax 

 is orange-brown, the ab- 

 domen, chocolate - brown. 

 Usually there is a light 

 longitudinal band in the 

 middle of the basal half of 

 the abdomen above, which 

 joins a semicircular band on the margin of the front half of the 

 abdomen (Fig. 363). Sometimes these light markings are wanting. 

 The male has stridulating organs. 



360 



Fig. 363. STEATODA BOREALIS 



