98 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



dibular plate elongate, truncate or broadly rounded in front, but not 

 emarginate. Palpi with short stout thumb, with one stout finger, and a 

 hair at one corner. Tarsi end in two long, simple, and but little curved 

 claws. Length, 0.4 mm. 



From Pullman, Washington, on timothy, in June (Hyslop, 

 coll.). 



Macrocheles canadensis, new species. 



Female. Pale yellowish, scutum rather darker; dorsum of body with 

 four rows of short, simple, curved spine-like bristles, one at humerus, 

 and about six along the hind margin. Legs quite slender, with long simple 

 bristles; leg I with the last joint a trifle longer than the preceding joint, 

 the antepenultimate joint still shorter; palpi with the last joint bristly 

 all over, other joints with few bristles only near tip, the penultimate joint 

 longer than either the preceding or the apical joint. Second pair of legs 

 about twice as heavy as the others; hind tarsi very long and slender. 

 Ventro-anal plate very broad, broadest much before the middle, truncate 

 in front, somewhat pentagonal in shape. .Length, 1.8 mm. 



Three from a guinea pig, Ottawa, Canada; sent by Dr. 

 Hewitt. 

 Histiogaster xylophaga, new species. 



Body elongate; in general similar to H.corticalis, but differing at once 

 in the absence of long bristles on tarsi and in the smaller bristles on ceph- 

 alothorax and abdomen. Tarsus I with numerous spines; tarsus n with 

 a large spine on outer side near tip and on inner side with a bristle; tarsus 

 III and IV with only two or three spines. Hind legs much smaller than fore 

 pairs and widely spearated from them; two pairs of fine hairs near tip 

 of the body, and two pairs on cephalothorax, the anterior pair on the 

 front margin; mandibles very large and stout. Length, 0.4 mm. 



Burrowing in stems (decayed) of alfalfa at Phoenix, Arizona; 

 sent by Dr. A. W. Morrill. The genus Histiogaster is dis- 

 tinguished from Monieziella by the presence of spines on 

 the tarsi; moreover, all Histiogasters are wood-feeders, while 

 Monieziella feeds on dead insects or on scale insects. 



Tarsonemus waitei, new species. 



Female. Body (including beak) not twice as long as broad, sides but 

 slightly curved, narrowed behind coxae III, where there are several long 

 spines on each side, behind this the body is broadly rounded, and below 

 slightly concave, being much thicker at hind coxa: than elsewhere. The 

 beak is very large and prominent, fully one-fourth as long as the body. 

 Legs I and II are very short and stout, leg III slender, leg IV extremely 

 tenuous and ending in two long bristles; all legs have only a very few 

 short, inconspicuous hairs; a long bristle above on each humerus. 



Male. The body is as long as in the female; the leg ill enlarged, while 

 the fourth pair are extremely large and long, and end in a very long claw. 



Length, 0.2 mm. 



