106 HYMENOPTERA. 



P. cressoiii, form mesill^ (Ckll.). 



1895, P. sudH/is, Fox, (female). Tr. Amer. Ent. Soc. 22:295. 



1896. P. ntesillcz, Ckll. (male). Can. Ent. 28:42. 

 1898. P ntesillce, Ckll. Can. Ent. 30: 237. 



1901. P. mesillce, Lov. Ent. News. 12:9. 



1901. P. ntesillce, Ckll. Ent. News. 12 : 39. 



imZ. P. rnesillcs, CkW. Psyche. 10:74. 



1904. P. mesillce, Vier. Can. Ent. 36:93. 



P. cressoni, form sanicul^ (Rob.). 

 1896. P. saniculcs, Rob. Can. Ent. 28 : 137. 

 1896. P. saniculce, Ckll. Psyche. 7 : 438. 

 1901. P. saniculce . \uOv . Ent. News. 12:5. 

 1904. P. sanicidce, Rob. Can. Ent. 36 : 273. 

 1910. P. sauiculce, 'Low. Psyche. 17:179. 



P. cressoni, var. magniclavis (Swk. and Ckll.). 

 1910. P. ;«a^«?V/az/w, Swk. and Ckll. Ent. News. 21:68. 



Typical Male. — Small, 3-5 mm. Distinguished by small size, dark 

 collar, and clavate, divergent (from orbit) upper extenson of lateral 

 face marks, which are not greatly narrowed at base. 



Very small, rather stout ; face broad above, rapidly narrowing below ; 

 clypeus rather short, base about equal in breadth to lateral face marks 

 at same level; scape short, stout, slightly concave exteriorly. 



Sculpture. — Front and vertex closely, confluently punctured, punc- 

 tures not extending onto occiput or cheeks ; mesonotum moderately 

 punctured with small round punctures ; scutellum similarly but more 

 sparsely punctured; metanotum rugulose or confluently punctured. 

 Propodeum normal ; bowl of enclosure broad, pitted ; neck narrow ; 

 lateral areas of posterior face almost smooth ; sides rugulose. Meso- 

 pleura rather closely punctured with larger punctures than those of 

 mesonotum ; metapleura striate. Abdomen impunctate, except for a 

 few sparse punctures of first segment. 



Yellow Markings. — Supraclypeal mark usually long, extending 

 above antennal sockets ; area below antennal sockets quadrate ; lateral 

 marks filling lateral areas and extending upward in long, rather stout, 

 somewhat clavate extensions, leaving orbital margin on level with base 

 of antennae, and projecting mesad, ending in slightly swollen tips 

 above antennal sockets, (figs. 78, 79). Scape with yellow stripe in 

 front ; tubercles with large yellow spot ; front of fore tibiae, basal third 

 of middle and hind tibiae, and basitarsi yellow. 



Genitalia. — Armature rather short and stout ; cardo short, rounded ; 

 stipes stout, superior lobe broad and long, extending about two-thirds 

 of way to apex, where it curves in almost abruptly ; apical portion 

 stout, more or less rounded at tip, moderately haired, with a tuft-like 



