NORTH AMERICAN HYMENOPTERA. 131 



while in O.vyhelu.'i the subniarginal cell is wanting, being merged into 

 the first discoidal cell ; the second discoidal cell in Oxybehm is short 

 and broad, in the Crabroninte long and narrow. The neuration of 



the Crabroninfe is very similar to 

 that of the genus Trypoxylon, but 

 in the hind wings it differs : in Try- 

 poxylon the neuration is complete, 

 the submedian cell long, narrow, 

 fully half as long as the median ; 

 in the Crabroninse it is incomplete. 

 Thorax of Goryus ,.ystuc..s Rafter chicfly through the absence of the 



Handlirsch), in detail, to explain the j^-,j^^,i„.^l pubital and discoidal 

 terms used in this paper, as applied to o ' 



the parts of the thorax. vcins beyond the median and sub- 



a, prosiernum ; P, pronotum ; c x «i '' 



dorsulum; ^, episternum mesopleuralis; nigdiail gells, and the submediau 

 /^ epimerum mesopleiiralis*; (c xy. rneso- 



pleura) ^, mesosternum ; A, sculellum ; cell is shorter, although itS length 

 I, metanotuni (postscutellum) ; i X /, me- , . 



tapleura (/t, episteinum ; /, epimerum); varies tO a Certain extent. In Eil- 

 »«, metasternum ; «, middle segment. . 



tomognathu.^, however, there is a 

 faint trace of the marginal vein beyond the median cell, which fact 

 further strengthens its right to generic rank. 



The three genera recognized in the present paper are distinguished 

 as follows : 



Eyes haiiy ; mandibles emarginate externally Entomognatlius Dahlb. 



Eyes naked ; mandibles entire externally. 

 Second discoidal cell long, narrow, much longer than the first, acuminate at tip, 

 or obtusely pointed ; epimerum mesopleuralis with a strong medial ridge, 

 extending from near the tegul?e to the medial suture of the mesosternum, 

 the anterior ridge of episternum mesopleuralis meeting it a little before 

 its termination. Abdomen strongly depressed, beneath subconcave. 



Anacrabro Pack. 

 Second discoidal short, shorter than the first, generally much so, at any rate 

 never longer, broadened and subtruncate at tip ; epimerum mesopleuralis 

 at the most with a ridge or crest just before the medial coxse, sometimes 

 entirely wanting, or represented by a small, pointed prominence. Abdo- 

 men but little depressed, convex above and beneath. Crabro Fab. (s. 1.) 



In the preparation of this paper it was found impossible to identify 

 the many subgenera and groups into which Cnibro has been divided. 

 Such confusion seems to exist in the work of the older European 

 authors that the identification of the groups is an impossibility, 

 without the aid of authentically determined specimens of European 



* 111 the Crahroninse this part is not restricted by a suture, «s in Gorytes, but includes 

 the greater portion of the mesopleurse, and the sternum does not extend on the sides as 

 shown in the above figure. 



TRANS. AM. ENT. SOC. XXII. MAY, 1895. 



