128 NORTH A.MEKICAN NYSSONIDAE (hYMENOPTERA) 



margin; antennae thickened apically, the hist segment elongate, straight, 

 acute, not excised behind, the penultimate segment long but not swollen, 

 the third segment longer than the short and subequal fourth or fifth. 



Pronotum with upper lateral angles entirely rounded. In most species 

 the part of the pronotum bordering the mesonotum forms a transverse nar- 

 row dorsal piece, rather sharply differentiated from the forward sloping 

 portion, but in this species this area merges gradually into the latter and is 

 scarcely distinct; mesonotum polished, with separated, round punctures; 

 scutellum margined, but not prominently so, flat and punctate, its surface 

 l)olished; mesojjlcura with sculj)ture largely obscured by vestiture, the epic- 

 nemial areas not se[)arated below and on the mesosternum by a carina; pro- 

 podeum rugose posteriorly, the dorsal surface with a row of elongate meshes. 



Dorsal surface of abdomen with shallow scattered punctures and obscure 

 interpunctulation, second ventral segment slightly produced medially at 

 base, but not truncate. 



//a^ito/.— California : Felton, Santa Cruz Mountains, May 20 

 to 25, 1907, 300 to 500 feet elevation, two males, (the author). 



Types.— UoMype, d^, Cornell University no. 139.1; paratype, 

 d", no. 139.2. 



This species couk^s nearest to srinplicornis of Fox, in which 

 species the scutellum is not margined, nor flat, the mesonotum 

 densely and coarsely punctate, and the size larger. Cameron's 

 cressoni known only from the female sex, also appears to be 

 allied. 



Nysson fParanysson) texanus Cresson 



(Ikokcia: Spiing Creek, Decatur County, July 1(3 to 29, 1912, one male, 

 (Cornell Univ. Expedition), [Cornell Univ.]; Waynesville, September 10, 1909, 

 one female, (the author), [Georgia State Collection]. Illinois: Virginia, 

 September 13, 1904, one female, (J. G. Needham), [Cornell Ihiiv.]. 



DIDINEIS 



Didineis nodosa Fox and peculiaris Fox together form a group 

 (>ntirely distinct from the other known species of the genus, by 

 reason of certain peculiarities of the males. These comprise 

 not only the curious structure of the antennae described and 

 ligured Ijy Vox, but, of greater importance, the structure of the 

 fore-legs. The front femora are greatly widened, lamelliform, 

 subti-iaugular, concave beneath, so as to form a shield-like cover 

 for llie tibiae, suggestive of the shield on the tibiae of certain 

 Crabronidac; the front tarsi are greatly widened and completely 

 flattened. 



