AMERICAN APTERA. 411 



abdomen to almost the middle of cephalothorax. Genital opening 

 almost round ; situated about three times its length in front of the much 

 larger anal opening. Anal opening broader posteriorly than anteriorly, 

 situated almost approximate to the posterior margin of ventral plate. 



Anterior pair of legs about two-thirds as long as abdomen ; distal 

 end of tarsus broad, this is only true, however, in the case of tarsus 

 one; tarsus two-thirds as long as tibia. Femur of leg two bearing 

 laterally a long, chitinous blade, the anterior cusp of which is as long 

 as the genual of same leg. Legs bearing three equal claws. 



Length, 0.48 mm. ; breadth, 0.24 mm. 



Under a log. Collected by the writer, Areola, Illinois. 

 Two specimens. 



Gen. ORIBATA Latr. 

 Body with smooth integument ; pteromorphae attached to 

 abdomen only ; claws tridactyle ; lamellae attached to the 

 cephalothorax for almost the entire length of their inner 

 margin. 



Four species. 



Key to the species described. 



1. Pseudostigmatic organs pectinate 2. 



Pseudostigmatic organs simple, smooth 3. 



2. Femora of legs with blade-like expansions on their inner margins. 



laminata. 

 Femora of legs without blade-like-expansions subaquila. 



3 . Translamella present figurata . 



No translamella present clavata. 



Oribata laminata n. sp. 



(Plate XV., Figs. 15, 16.) 



Light brown; surface of integument smooth. 



Cephalothorax long and narrow ; lamellae about three-fifths as long 

 as cephalothorax, without cusps and very narrow ; translamellse absent. 

 There is a large pair of tectopedia for the protection of coxa one. 

 Lamellar hairs somewhat longer than lamella?, straight and directed 

 forwards; interlamellar hairs similar to lamellar hairs but more erect. 

 Anterior lateral hairs pectinate, about as long as lamellae, curved 

 markedly towards the median plane. Pseudostigmatic organ with 

 short, slightly recurved peduncle and enlarged, oblong head. Palpi 

 prominent. 



Abdomen twice as long as broad ; pteromorphae truncate, not ex- 

 tending beyond the anterior marging of abdomen and attached to the 

 anterior one-half of the lateral line of the same. Genital covers twice 

 as long as broad, situated about twice their length in front of the larger 



TRANS. AM. ENT. SOC, XXXV. NOVEMBER, 1909 



