Sept.. I909.1 EWING : NeW AMERICAN ORIIiATOIUEA. 123 



longer and slightly curved. There is a lateral pair of bristles situated just below the 

 anterior end of the lateral lamellce. They are large, curved, pectinate and inclined 

 towards the median plane. Pseudostigmatic organ with short peduncle and large, 

 oblong, clavate head. 



Abdomen two thirds as broad as long ; pteromorpha; truncate, not extending 

 beyond the anterior margin of abdomen. Genital covers two thirds as long as anal 

 covers and situated about one and one half times their length in front of the latter. 



Legs of medium size ; tarsus and tibia subequal ; femur subglobose. Ungues 

 tridactyle. The legs bear many rather short, curved, pectinate bristles. 



Length, 0.35 mm.; breadth, 0.22 mm. 



Under logs. Collected by the author, I'rbana, Illinois. One 

 specimen. 



Genus ORIBATELLA Banks. 



^^'ithout spatulate hairs ; body ne\er pitted ; wings of abdomen 

 never attached to cephalothorax ; lamellae large and attached to the 

 dorso-vertex by their posterior margins only. 



This genus is rich in species in this country but in Europe is not 

 so well represented. 



Oribatella magniseta, new species. (Plate IV, Fig. 15.) 



Black ; integument thick and reticulate. 



Cephalothorax one third as long as abdomen; lamella" very large, almost com- 

 pletely obscuring the cephalothorax, attached by the posterior margin only, bifid in 

 front. The anterior pair of lamellar cusps are as long as the rest of the lamellie and 

 extend beyond the tip of the rostrum. Lateral lamellre very broad, truncate in front 

 and not extending beyond the middle of the cephalothorax. No translamelia. 

 Lamellar hairs long, straight, slightly pectinate, and as long as the lamellae from 

 which they extend. Interlamellar hairs erect and equal to lamellar hairs ; anterior 

 lateral hairs two thirds as long as lamellar hairs, much curved and strongly pectinate- 

 Pseudostigmatic organ erect, elongo clavate, pectinate. 



Abdomen subglobose ; pteromorphse two thirds as long as the abdomen, slightly 

 pointed in front, but not extending beyond the anterior margin of the abdomen. 

 Genital covers equal to anal covers and situated twice their length in front of the 

 latter. The dorsum of abdomen has on each side eleven enormous, straight, slightly 

 pectinate bristles ; three along the margin of attachment of ihe pteromorphs with the 

 abdomen, four in a longitudinal row near the median plane, and four situated on the 

 posterior latero-dorsal aspect. 



Legs of moderate length and bearing conspicuous, curved, dentate bristles. 

 Ungues tridactyle. 



Length, 0.72 mm.; breadth, 0.56 mm. 



Under stones. Collected by myself at Dmining, Illinois. Sev- 

 eral specimens. 



