AMERICAN HYMENOPTERA. 195 



A Coiitribiitioii towards the kiiowled$;e 4»rtlio Odyncridif 

 of the Soiithwe»«t of tlie United Ktatex. 



BY P. CAMERON. 



The species recorded and described in this paper were sent irie hv 

 Prof. C. F. Baker. The Vespidse of Nevada, California and Texas 

 are comparatively little known. In point of fact not much has 

 been done towards the elucidation of the Solitary Wasps of the 

 United States since the appearance of the well-known monograph 

 of Dr. Henri de Saussure. I hope shortly to prepare and publish a 

 synoptical table of the North American species. 



iMoiiobia qiiadrideiis Say. 

 Fedor, Texas. 



A variable species as regards the size and form of the yellow 



markings. 



Odynern!« arvensis Sauss. 



The four examples of this species examined are not alike. In 



none of theni is the apex of the clypeus quite as shown bv Saussure 



(Syn. Am. Wasps, f. 16«), but then its apex is not identical in 



Prof. Baker's specimens which are from Texas (Fedor). The 



black apical mark on the clypeus varies in size and form ; it may 



be regular or iri-egular ; . the extreme apex may be black, red, or 



have two small yellow marks. The black apical mark on the first 



abdominal segment varies in size and form ; in one specimen it is 



small, narrowed greatly at the base and apex, dilated laterally, the 



lateral projection being wide on the inner, gradually narrowed on 



the outerside. The legs are reddish or yellow, tinged with rufous. 



The head and thorax are densely covered with gray pubescence. In 



all the specimens there is a large yellow or rufous spot on the sides 



of tlie scutellum. Apical half of mandibles rufous, the black basal 



half with a yellow mark. There may be a small yellow lateral 



mark on the second abdominal segment. 



Odyneru»$ aniiiilatiis Say. 



This is a most variable species as regards coloration ; the scul})- 



ture varying also, some specimens being much more strongly punc 



tured than others. Some specimens have the wings more deeply 



and broadly fuscous-violaceous than others. Other exan)ples come 



TEANS. AM. ENT. SOC. XXXIV. JULY. 1908, 



