MONOGRAPH OF THE NORTH AMERICAN PROCTOTRYPID.E. 63 



Mesitius, while its supposed S , Omilusfii.seieornis Jurine, is a genuine 

 Isobrachium. An error of this kind does not necessarily invalidate 

 the genus, the male still holding good as the type of the genus. A 

 male specimen of Omahis fmeicornis is in my collection, and although 

 it closely resembles males of Epuris and Mesitius it is quite distinct, as 

 I have pointed out, and it is here made the type of the genus Tsohm- 

 cliium Forster. 



The following table will l>e found useful in separating the North 

 American species: 



TABLE OF SPECIES. 



Coxae and legs pale rufous or houey-yellow 2 



Coxiii ami femora black; -wings subhyaline or fuscous. 



Antcnuic and legs black, the tarsi fuscous <? M. monticola Ashm. 



Autcuntc and legs dark rufous 9 M. vaxcouverensis, sp. nov. 



Front coxte and femora black, middle and posterior femora rufous, or only 

 slightly dusky. 

 Trochanters, tibia?, and tarsi rufous. 



Wings subfuscous $ M. nevadexsis, sp. nov. 



Wings hyaline. 

 Anterior tibite and tarsi and middle and posterior legs fuscous; antennje 



dark fuscous <J M. minutus, sp. nov. 



Anterior tibiie and tarsi and middle and posterior legs, brownish-yellow; 

 their femora more or less dusky; antennrc rufous 5 . 



M. CALIFORNICUS, sp. nOV. 



2. Wings subhyaline. 



Legs brownish-yellow or pale rufous. 

 Tip of abdomen not rufous; metathorax with about 7 raised lines, the lateral 

 altbreviated ; ^ antenuic fuscous ; 9 antenna^ yellow. 



M. BIFOVEOLATUS, Sp. UOV. 



Tip of abdomen rufous ; metathorax with about 12 raised lines 9 . 



M. TEXANUS, sp. nov. 

 Wings not fully developed, reaching only slightly beyond base of abdomen. 



Legs rufous M. brachypterus, sp. nov. 



Mesitius monticola Ashm. 



Eiiyris monticola Ashm. Bull. No. 1, Col. Biol. Assoc, p. 8. 1890, ^ . 



$ .' Length -4""". Black, smooth, shining. Head sparsely punctate, 

 each ocellus surrounded in front by a depression. Autenme black, 

 covered with a fuscous pubescence, 13-jointed, reaching to the middle 

 of the metathorax, the first joint the thickest, the length of the fourth, 

 the second joint the shortest, the third slightly longer, the fourth and 

 following joints slightly longer than the third and about of an equal 

 length or very nearly so ; terminally the antennte are a little thinner than 

 at base. Thorax above with some rather long, fuscous hairs, trapezoidal,' 

 the mesonotum with two grooves, slightly convergiu^c toward each other 

 posteriorly but still widely separated. Scutellum flattened, with two 

 small, widely- separated fovese at base, each fovea being exactly opposite 



