NO. 1866. NEW SAW FLIES IN V. S. NATIONAL MUSEUM— ROHWER. 385 



form fovea; postocellar furrow curved anteriorly; antennae nearly 

 filiform, the tliird joint a little longer than the fourth; stigma rounded 

 below; sheath as in figure. Black; clypeus, labrum, mandibles (apices 

 piceous), pronotum, tegulse, mesoprescutum, sides of mesoscutum, 

 mesoepisternum, apical two abdominal segments, legs below middle 

 of coxae rufo-ferruginous ; wings hyahne shghtly yellowish ; venation 

 yellowish-brown, darker basally. 



The clypeus is normally black. 



Colorado. Five females from the C. F. Baker collection. 



Type.— Cd^t. No. 13839, U.S.N.M. - 



Related to spissipes (Cresson), but may be distinguished by the 

 shape of the sheath and somewhat different conformation of the head. 



CRATEROCERCUS, new genus. 



Belongs near Hemichroa Stephens, but has the antennge shorter 

 and stouter; the malar space wanting; the eyes longer; the head and 

 thorax pimctured ; and the second recurrent vein usually received by 

 the third cubital cell. Also much Uke Mesoneura Hartig, which 

 belongs to the same tribe, in body characters, but differs in the robust 

 cerci, position of lateral ocelli, and contracted anal cell. 



Clypeus deeply emarginate; eyes elongate, reniform; malar space 

 very narrow, wanting; head large, broader than high; oceUi in a low 

 triangle, the lateral ones nearly touching the supraorbital hne; 

 antennae robust, rather short, pedicellum short, much wider than 

 long, third and fourth joints subequal; head and thorax dull, punc- 

 tured or granular; thorax similar to Hemichroa; legs as in Hemichroa; 

 tarsal claws cleft ; second recurrent vein usually received by the tliird 

 cubital cell, or sometimes interstitial with the second transverse 

 cubitus; last ventral plate produced in the middle; sheath robust; 

 cerci very short, robust; hypopygidium very elongate; no prode- 

 centia. 



Genotype. — Hemichroa phytophagica Dyar. 



Hemichroa alhidovariata Norton and Hemichroa fraternalis Norton 

 also belong to this genus. 



Genus MARLATTIA Ashmead. 

 MARLATTIA ERYTHROTHORAX, new species. 



Head and abdomen black; thorax and legs reddish. 



Female. — Length 4.5 mm. Clypeus arcuately emarginate, lobes 

 broad rounded; supraclypeal suture strong; supraclypeal area trian- 

 gular in outhne, shghtly convex; antennal fovege not large; middle 

 fovea elongate and connected with the poorly defined ocellar depres- 

 sion; postocellar hne subequal with the ocellorbital Une; lateral 

 oceUi much above the supraorbital line ; postocellar area much wider 

 94428°— Proc.N.M.vol.41— 11 25 



