92 



Alexander Petriinkevitch, 



typical, one-jointed. First femur 5.2 mm. long, second 6.1 mm., 

 third 6.9 mm., fourth 6.1 mm. 



Found in the Pennsylvanic (Lower Allegheny) of Mazon Creek, 

 Illinois. 



Fig. 56. 

 Daniels coll., showing 



Figure ^^. — Arihrolycosa danielsi n. sp., holotype, 



the ventral surface of the specimen as it appears on the nodule. Figure 56 



1 



Same, showing dorsal view of the body. 



X 



ORDER ANTHRACOMARTI 



Head completely fused ^^^th thorax. Abdomen segmented, the 

 anal operculum representing probably the eleventh abdominal seg- 

 ment. Dorsal surface of abdomen divided into three or five longi- 

 tudinal areas, the central one formed by the tergites, the lateral ones 

 by the pleural sclerites. Chehcera not known. Pedipalpi pediform. 

 Legs seven-jointed, with movable coxae, apparently articulated to a 

 sternum. 



Pocock, who made a careful study of this oder and has had more 

 species before him than are known to occur in North America, de- 

 scribes the morphology of the abdomen in his Monograph as follows : 



" Opisthosoma without appendages, movably jointed to the pro- 

 soma, but with its individual segme ts apparently welded together, 

 though the sutural lines persist. Seven tergal plates are always 



