PECKHAM. [Vol. 2, 



MARPTUSA THORELL. 

 Plate VIII., Figs. 1—16, and 2—26. 



Spiders rather large and flat; abdomen large and wide, 

 with central longitudinal light band. Colors usually dull. 



The cephalothorax is long, wide, flat and low. It is widest 

 behind the dorsal eyes. The sides are more or less rounded, 

 and are parallel as far as the second row of eyes. The quad- 

 rangle of the eyes is about one-fourth wider than long, is 

 equally wide in front and behind, or a little wider in front (in 

 M. millerii, slightly wider behind), and occupies very little 

 more than one-third of the length of the cephalothorax. The 

 eyes of the first row are small. This row is straight, or a little 

 curved. The middle eyes are close together and are about twice 

 as large as the lateral, which are usually well separated from 

 them. 



The second row is half-way between the first and third 

 rows, or a little nearer the first. The dorsal eyes are smaller 

 than the lateral and form a row which is plainly narrower than 

 the cephalothorax at that place. These eyes are placed plainh^ 

 on the upper surface of the cephalothorax, not on the sides, 

 and are much further from each other than from the lateral 

 borders. 



The legs are usually 1423 in the male and 4132 in the 

 female, the second and third pairs being very nearly equal. 



This genus stands at the head of the group. It is most 

 likely to be confused with Breda, as the colors, markings and 

 general appearance are very similar, but Breda is not quite so 

 flat either in the cephalothorax or the abdomen, and has the 

 iniddle eyes of the first row much larger and more prominent, 

 while the cephalic part is relatively a little longer, occupying 

 nearly two-fifths of the cephalothorax. In Mendoza the species 

 are smaller and are not at all flattened, and the quadrangle 

 of the eyes is wider behind. The shape of the cephalothorax 

 differs from that of Epinga. 



