Superfamily Argiopoidea 



The sternum is dark around the edges, and the whole under 

 side of the abdomen is gray, darkest at the sides, with two in- 

 distinct light lines converging toward the spinnerets." 



"The tibia of the male palpus is as short as the patella. 

 The process of the tibia is as long as the diameter of the joint. 

 It is flat and widened at the end, hollowed in the middle, and with 

 the corners sharp, and sometimes two little teeth in the hollow. 

 The palpal organ resembles that of the other species." 



The epigynum is of the form shown in Fig. 703. 



The Six-dotted Dolomedes, Dolomedes sexpunctatus (D. 

 sex-punc-ta'tus). — This is a beautiful and easily recognized species. 

 It is dark greenish gray in colour, with a white band on each side 

 extending the whole length of the body, two rows of white spots 

 on the surface of the abdomen, and six dark dots on the sternum, 

 three on each side near the coxae. It was probably the presence 

 of the six dark dots on the sternum that suggested the specific 

 name. The adult measures from three fifths to four fifths inch 

 in length. The legs of the male (Fig. 704) are very long, while 

 those of the female (Fig. 705) are of moderate length. 



This beautiful species is common in marshy places. It 

 lives on plants over water; and dives freely when frightened, 

 hiding under floating leaves. It is widely distributed, ha\ i ;. 

 been found from New England to Texas. 



There is some doubt whether our Dolomedes which are marked 

 as described above represent a single variable species or more 

 than one species. I have seen only a single type of female, 

 the epigynum of which is represented by Fig. 706. I have 

 before me, however, two easily separated types of males, which can 

 be distinguished as follows: 



Type a. — In this form the width of the clypeus is about 

 equal to the space between the anterior median eyes and the 

 posterior median eyes; the posterior median eyes are but little 

 if at all larger than the anterior median eyes; the anterior row of 

 eyes is longer than in Type b; and the femur of the fourth pair 

 of legs lacks the spinose hump characteristic of Type b. 



Type b. — This type of male is easily recognized by the 

 presence of a spinose hump under the femur of the fourth legs. 

 The width of the clypeus is two or three times as great as the 

 space between the anterior median eyes and the posterior median 

 eyes; the posterior median eyes are much larger than the anterior 



614 



