1 90 AXEL LEONARD ME LANDER 



Type. Pal. Coll. No. 9242. 



In the collection is another specimen (No. 9246) exhibiting 

 the base of the head, the meso- and metathorax, and the base of 

 the abdomen, together with a portion of the wings. The insect 

 is of the same size as the specimen previously described, and 

 appears to belong to the same species. Nothing further can be 

 supplied to the diagnosis by the characters exhibited by this 

 fossil. In its broadened wings the straight mediastinal and 

 scapular veins alone are clearly cut, the other veins being 

 indefinitely preserved. 



17. Eucaenus attenuatus sp. nov. (Plate VI, Fig. 4; Plate VII, Fig. 11). 



Head indefinite, but with a median carina; prothorax more 

 or less quadrate, its sides nearly parallel ; mesothorax trans- 

 versely quadrate, much broader than long; metathorax and 

 abdomen indefinite, but stout, ovate-pointed caudally ; abdomen 

 with nine uniform segments, the apical small, the last two seg- 

 ments with a sharp median keel. Legs compressed, rather short 

 and stout, minutely punctate, the hind tarsi longer than the 

 tibiae. Wings large, not abrupt at the humeral angle, uniformly 

 elongate-oval ; mediastinal vein nearly straight, oblique, meeting 

 the costa at the outer three-fourths, provided with numerous 

 oblique cross-veins to the margin ; scapular vein close to the 

 mediastinal, parallel with it, and slightly curved so that the 

 wing-margin and the scapular vein outline an elongate spindle- 

 shaped area ; the remaining veins obliterated. 



Length about 28"°^, length of wing about 25™™, breadth of 

 wing 9°"". 



One specimen, an ironstone concretion from the Egan col- 

 lection of the Chicago Academy of Sciences, No. 4749. Mazon 

 creek. 



The three species of this genus show the following inter- 

 relationship: 



Last abdominal segments provided with a median keel - - - 2 

 Last abdominal segments not carinate, costa and scapular vein opposedly 



curved ---_-..- attenuatus sp. nov, 



2. Scapular vein curved in an opposite sense to the costal margin 



niazo7ius sp. nov. 



Scapular vein subparallel with the margin - - ovalis Scudder 



