326 AMERICAN HYMENOPTERA. 



as the head and thorax united. The stout antennae are placed immediately over 

 the face. 



Canada. Allied apparently to S. canadensis Sauss., the descrip- 

 tion of which is very defective, as is admitted by Saussure, cf. Syn. 

 Am. Wasps, 157. 



Syinmorplius albomarKinatus Sauss. 



I have examined a 9 and % of what may be this species from 

 Montreal. They are barely 7 mm. long (total length). The cly- 

 peus ( 9 ) is as long as broad, is very shining, very sparsely weakly 

 punctured ; its apex ends in two distinct teeth, but is not deeply 

 incised. Thorax more than twice longer than wide, transverse at 

 the base, without distinct lateral angles ; parapsidal furrows dis- 

 tinct at base only. Scutellum with a distinct, deep furrow down the 

 apical three-fourths. Postscutellum prominent, rugosely punctured, 

 the apex smooth, broadly rounded. Base of metanotum coarsely 

 rugosely punctured, reticulated, the sides bordered by a keel ; there 

 is a keel down the centre of the apex, which is finely transversely 

 striated. Upper half of mesopleurae strongly punctured, the lower 

 almost smooth ; the two parts are separated by a furrow ; the upper 

 part of metapleurse coarsely longitudinally aciculated, the lower 

 raised, smooth, shining. The first abdominal segment is strongly 

 punctured, the punctures clearly separated ; the basal slope bordered 

 by a ridge ; the 2ud segment is slightly longer than wide, smooth, 

 narrowed at the base. The apices of the tibise are broadlj' infus- 

 cated. 



The % has the clypeus yellow ; it is, if anything, longer than 

 wide, almost smooth, its apex roundly incised ; the mandibles are 

 largely yellow at the base. The antennae are stout, thickened to- 

 wards the apex, which has no hook. In both sexes there is a yellow 

 spot on the apex of the antennal scape. In the 9 there is no yel- 

 low line on the 3rd abdominal segment, but a narrow, obscure one 

 on the 4th ; in the % there is a narrow line on the 3rd, but none on 

 the 4th. 



S. cogitans, described in this paper, is closely allied ; it may be 

 readily separated by the base of the thorax being round, not trans- 

 verse, without lateral angles; it is also longer, compared with the 

 width, the part behind the tegulse being longer, compared with the 

 anterior part, and the apex of the clypeus has not the sides ending 

 in such distinct teeth. 



