80 



Alexntidcr PctriDikcvitch, 



excepting on tlie brief first (= third, A. P.) abdominal segment 

 which is only punctate along its hinder edge " (Scudder, 1890, 

 p. 444). 



One pair of shorter, inner, and one pair of oblique, longer, outer 

 lines divide the second, third and fourth visible tergites into five 

 fields of which the middle one is the widest. Along the posterior 

 edge of the first, second and third visible tergites runs a row of 

 punctate depressions, much heavier than those covering the rest 

 of the body and the legs. 



The reverse of the specimen shows clearly that the cucuUus was 

 anteriorly bent downward, much as is the case in recent Ricunlei, 

 and appears in form of a punctate, trian- 

 gular plate. Behind it is an almost smooth 

 transverse area, jirobably the coxae of the 

 ])e(lij:)alpi. The long and narrow coxae of 

 the first pair of legs, and the triangular 

 coxae of the second pair are almost smooth, 

 those of the third and fourth pair punctate 

 like the dorsal surface of the abdomen. 

 Between the widely distant second coxae 

 is visible a dark plate with a narrow anterior 

 process scjmrating the first coxae. This 

 plate is probably the anterior part of the 

 sternum, which is hidden posteriorly by 

 the contiguous third and fourth coxae. 



Only three abdominal sternites are visible, 

 belonging to the fourth, fifth and sixth 

 segments, with a row of deep round de- 

 pressions along the posterior edge of the first and second visible 

 sternite. Covering the edge of the abdominal sternites is the un- 

 segmented pleura, the lines simulating segmentation evidently due 

 to artificial folding. 



A second specimen, in the collection of Mr. L. E. Daniels, is not 

 so well preserved as the type, yet shows sufficiently clearly all struc- 

 tures as to leave no doubt of it belonging to the same species. The 

 pleura in this specimen shows no artificial segmentation, but is 

 folded longitudinally. Total length 12.5 mm. Width of abdomen 

 6.0 mm. 



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

 Illinois. 



Fig- 45- 

 Fifjure 45. — Same, vcn- 

 siirfaro, sliovving 



tral 



coxae and sternites. X 



