300 PROCEEDINGS OF THE ACADEMY OF [March, 



lothorax as 1:6. Quadrilateral of the posterior eyes broader than 

 long. 



Form. — Cephalothorax flat and broad, the cephalic portion clearly 

 marked off from the thoracic, in front fully ( 9 ) or less (d^) than one- 

 half its greatest transverse diameter, highest at posterior eyes ; in the 9 

 the dorsal outline gradually declines to the posterior margin with a 

 posterior declivity only slightly defined, but in the (j the posterior 

 declivity is well marked from the dorsal outline. Chelicera massive, 

 their length more than twice the height of the head in front, longer 

 than the width of the clypeus, with 3 pairs of teeth. Labium longer 

 than wide, broadest at the tip where it is truncated, one-half the length 

 of the maxillae. Sternum longer than broad. Posterior spinnerets 

 longest. Legs thick, length of leg IV to cephalothorax, c^ 3.6 : 1, 

 9 3.2 : 1; metatarsus IV shorter than patella and tibia combined. 



Genus TROCHOSA C. Koch, 1848. 



This genus is most closely allied to Lycosa, and differs from it mainly 

 in the following characters : The first row of eyes is fully as wide as the 

 second, or at least (as in avara and contestata) the middle points of the 

 lateral eyes of the first row are as far lateral as the middle points of 

 the eyes of the second row; the sides of the head are obliquely arched, 

 and the cephalothorax highest at or behind the middle (except in the 9 

 of frondicola) ; the legs are usually comparatively short (only in cinerea 

 has leg IV a length of four times the cephalothorax), and their spines 

 are usually short (in rubicunda there is only one ventral spine on tibia 

 I). The posterior spinnerets are never longer, usually shorter than the 

 anterior. Metatarsus IV is always shorter than the patella and tibia 

 combined. The chelicera are robust and arched anteriorly, with 3 

 teeth on their posterior margins (4 in contestata), and their length is 

 fully twice the height of the head in front. The length of the dorsal 

 eye area to the cephalothorax varies from 1 : 4.5 (cinerea) to 1 : 9 

 (rubicunda). The labium is longer than wide, and frequently one-half 

 or more the length of the maxillse (septdchrcdis, frondicola, furcelli, 

 cinerea). 



There is a greater structural difference between Trochosa rubicunda 

 and Lycosa scutulata, than between the latter and Pardosa; so that if 

 we maintain the genus Pardosa we must also retain Trochosa. 



Key to Species of Trochosa. 



a. 1. — Dorsal eye area one-ninth the length of the cephalothorax, one 

 spine on the ventral surface of tibia I, . . . rubicunda. 



