Superfamily Argiopoidea 



been known as Dolomedes lanceolatus. I have not found the 

 two together; but Mr. Banks assures me that there cannot be 

 the slightest doubt that urinator and lanceolatus are the two 

 sexes of the same species. Both were described by Hentz at 

 the same time; but as the description of D. urinator precedes 

 that of D. lanceolatus, the former name is used for the species. 



In the male, the margin of the cephalothorax is black; just 

 within this black margin, which is quite narrow, there is a broad 

 yellowish band which completely surrounds the disk except that 

 it is interrupted next the abdomen. On each side of the abdomen 

 there is a yellowish band; from each of which there extend toward 

 the disk on the hind half of the abdomen two short branches. 



This species is usually found on or near water, running on it 

 with surprising agility, preying often on large aquatic insects. 

 It can dive and stay a considerable time under water to avoid its 

 enemies. These facts were noted by Hentz and the specific name 

 given to the female by him was suggested by them. But other 

 species of Dolomedes dive as freely as does this one. 



The adult female was taken near Ithaca, N. Y., on her nursery 

 in August; at the same time half-grown females were taken. 

 From this 1 infer that it requires two years for this spider to 

 reach maturity. 



Dolomedes vernalis (D. ver-na'lis).— - This species, recently 

 described by Emerton ('09), is much less common than either 

 of the preceding species of Dolomedes, although it is quite widely 

 distributed in the Northeastern States and Canada. 1 have seen 

 only the female (Fig. 702), which 1 collected at Ithaca, N. Y.; 

 but Hmerton states that the colours and markings of the two sexes 

 are the same. The cephalothorax of the male measures from 

 one eighth to one sixth inch in length and a little less in width; 

 that of the female measures about one fourth inch, and the ab- 

 domen is of the same length. 'The colours are pale yellow and 

 gray. The cephalothorax is dark in the middle and light at the 

 sides, with light gray spots over the coxae. The dark middle 

 area extends forward between the eyes to the front edge of the 

 head, dividing into two below the eyes. The chelicerae are striped 

 on the front with black. The abdomen is light at the sides, and 

 the middle dark marks are united into a broad stripe with irregu- 

 larly indented edges. The legs are marked with broken dark 

 rings, the femur and the tibia having parts of lour rings each. 



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