12 PROCEEDINGS OF THE NATIONAL MUSEUM vol.80 



1. MACROCENTRUS INCOMPLETUS, new species 



In the short maxillary palpi, the unusually short and broad face, 

 the strongly convex vertex, the broad temples and cheeks, the non- 

 prominent eyes, and the absence of distinct teeth on the outer apical 

 margins of the trochanters, this species most closely resembles ci'as- 

 sipes, but it is at once distinguished from all other known North 

 American species of Maerocentrvis by the absence of the second inter- 

 cubitus, the strongly inclivous nervellus, the unusually short lovs^er 

 abscissa of basella, and the small number of segments in the anten- 

 nae; from crassipes it differs further in having very slender legs 

 and in the much smoother thorax and abdomen. 



Female. — Length 3.5 mm. Head less transverse than is usual in 

 Macroce7itriis^ the temples conspicuously broad and bulging; eyes 

 small and not extending beyond the outer limits of the temples, but 

 situated low so that malar space is short and the vertex broad and 

 strongly convex; face more than twice as broad as long; mandibles 

 long; clypeus fully three times as broad at apex as long, the anterior 

 margin truncate; interfoveal line twice the length of clypeus; 

 maxillary palpi scarcely as long as height of head, the longest seg- 

 ment much shorter than the scape ; face, clypeus, f rons, temples, and 

 cheeks smooth and polished; ocelli small, ocell-ocular line nearly 

 three times the diameter of an ocellus ; antennae very nearly as long 

 as the body, 27-segmented in type. 



Thorax rather stout; middle lobe of mesoscutum elevated a little 

 above the level of lateral lobes; mesopleura polished; metapleura 

 smooth; propodeum mostly smooth, weakly roughened down the 

 middle and at apex; legs very slender; trochanters without teeth 

 outwardly at apex ; longer calcarium of posterior tibia less than one- 

 third the basitarsus ; anterior wing with second intercubitus wanting ; 

 the radius usually not distinctly divided into three abscissae; first 

 discoidal cell much longer than first cubital ; veins in apical third of 

 wing faint ; nervulus very weakly postf ureal ; submedian cell closely 

 hairy ; posterior wing with nervellus strongly inclivous, usually about 

 twice as long as lower abscissa of basella, the latter hardly one-fourth 

 the mediella ; radiella faint. 



Abdomen as long as head and thorax combined, somewhat com- 

 pressed at apex, smooth and polished, with only very faint sugges- 

 tion of sculpture on first tergite; first tergite more than twice as 

 long as broad at apex; ovipositor sheaths longer than the abdomen 

 but distinctly shorter than the thorax and abdomen combined. 



Head black; clypeus, and the mandibles except at apex, ferrugi- 

 nous ; antennae piceous to blackish ; thorax yellow-ferruginous, with 

 the metanotum, propodeum, and more or less of the pleura piceous 

 to blackish; abdomen piceous, blackish at apex; legs entirely testa- 



