OF WASHINGTON, VOLUME XI, 1909. 139 



lamella is divided in two points at tip, the inner one much the shorter, 

 and from between them arises a large, stout, serrate bristle ; superior 

 longer, and serrate ; pseudostigmatic organ rather short, capitate ; 

 beneath, on each side of the cephalothorax in front of leg I is a long 

 spine-like process tipped by a stout, incurved, serrate bristle. Legs of 

 moderate length, tarsi with many hairs, some beneath are large and 

 serrate ; patella and tibia I and II each with a prominent thickened hair 

 or bristle near tip. Abdomen plainly longer than broad, broadest behind, 

 with six short stiff, rather thick hairs each side, and two on each wing 

 above, and two each side on posterior margin lower down than the 

 others. Venter smooth, genital opening broader in front than long, 

 nearly twice its length in front of the much larger anal aperture, which 

 is broader behind than in front ; sternal plate not separated from venter, 

 and showing three short lines each side : a large tectopedium behind 

 coxa I, with a serrate bristle beneath. 



Length, 0.5 mm. 



From Guelph, Ontario, Canada ; from under bark of various 

 trees, as mountain ash, April 17; Norway spruce, February 27; 

 catalpa, February 14; balsam, February 13. 



Liacarus parvulus, new species. 



Reddish brown, or more yellowish. Body globose, high ; cephalo- 

 thorax very short and depressed, the lateral lamellae very small, and 

 terminated by a small hair ; no superior bristles visible ; the pseudo- 

 stigmatic organs quite long, clavate at tip ; body smooth, no hairs, 

 broader behind than in front ; a curved plate behind coxse I ; legs short, 

 three equal claws, the hairs of legs simple, one near tip of penultimate 

 joint very long. Venter smooth ; genital aperture one and one-half 

 times its length in front of the slightly larger anal opening; in front of 

 the genital aperture there is a broad transverse plate, concave in front, 

 its outer anterior corners extended ; it is thicker than the rest of the 

 skeleton and darker colored ; at its sides the sternal plate is divided 

 by a line and dot. 



Length, 0.4 mm. 



Near L. nitidus, but smaller, and no visible superior bristles. 



Guelph, Ontario, Canada ; from moss on a stump, April 26. 



Oribata canadensis, new species. 



Yellowish brown. Cephalothorax with a pair of curved anterior 

 bristles ; superior bristles, erect, stiff, close to the pseudostigma ; the 

 pseudostigmatic organ longer than the width of the cephalothorax, 

 barely thickened at end, straight. Abdomen globose, smooth, with a 

 submedian row each side of eight stiff, erect bristles, and at tip a pair 

 of curved hairs, and at base a pair close together projecting over the 

 cephalothorax. Legs long and slender, with slender hairs, one above 



