THE TENTHREDINOIDEA 347 



Family NEMATIDiE. 



PACHYNEMATUS OCREATUS. 



Pachynematus ocreaius Harrington, Can. Ent., xxi, p. 25, 1889. (Nema- 

 tus.) 



Three females taken at Sitka, Alaska. This species was originally 

 described from Ottawa, Ontario. 



PACHYNEMATUS AFFINIS. 



Pachynematus affinis IMarlatt, Revision of the Nematina; of North Amer- 

 ica, p. 97, 1896. 



One female and one male, Popof Island, Alaska, July 13, 1899. 

 The only observed differences between the type of ajffinis and the 

 Alaska form are in coloration. In the latter a small black spot is 

 present on the pectus, and the antennae are inclined to be testaceous 

 towards tip. P. affinis was originally described from Montana. 



PACHYNEMATUS ORONUS sp. nov. 



Female : Length 6 to 7 mm. ; clypeus narrowly and deeply notched, 

 lobes triangular ; frontal crest broad and strong, extending laterally to 

 orbits, notched in the middle ; sides of ocellar basin broad and rounded ; 

 antennal fovea oval, deep, continuous posteriorly with the frontal de- 

 pression ; antennas longer than head and thorax, slender, third joint 

 slightly shorter than fourth ; venation normal except that the third 

 cubital cell is three times as long as wide at base, the sides almost 

 parallel ; stigma rather narrow, gently rounded below ; sheath narrow, 

 rounding above and below to a rather narrowly rounded tip ; cerci 

 extremely long, somewhat clavate at apex ; inner tooth of claw mi- 

 nute. Color for the most part reddish yellow ; ocelli, two basal joints 

 of antennae, spot on anterior lobes of mesonotum sometimes absent, 

 variable spot on pectus, basal plates, tergum of abdomen except three 

 or four apical segments, black ; venter more or less infuscated basally ; 

 wings hyaline, nei"vures brown, stigma and costa yellowish. 



Thi-ee females, Yakutat Bay, Alaska, June 21, 1S99. 



Type no. 5285, U. S. National Museum. 



This species is allied to the preceding form, but differs in the more 

 deeply emarginate clypeus and in the absence of black markings on 

 the mesonotum. 



