ODYNERUS. 115 



Var. The head more or less obscure, passing into black or 

 quite brick-red. 



9 . Clypeus pyriform, coarsely punctate, terminating with two 

 small brown approximating teeth. 



%. Head blackish or black ; orbits rufous; inner margin of the 

 eyes, a frontal spot, and a line on the mandibles, pale yellow ; 

 the scape at times with. a } ;r ellow line; clypeus polygonal, strongly 

 bidentate, pale yellow. .Anterior femora and tibiae yellowish 

 before (Bahia Blanca). 



The male is described from a southern specimen, which may be 

 the reason of its black head. Specimens from Buenos Ayres may 

 have the head red like the females? 



Eess. a. diff. — This is a quite distinct species in the form of 

 the thorax. It has also a different appearance from all other 

 Ancistrocerus. 



Hob. The Argentine Republic, 5 9,4 %. Buenos Ayres 

 (Meyer Durr), 19,3$. Bahia Blanca (G. Claraz). 



D. Form very stubbed. Thorax cubical, nearly as long as ivide. 



.20. A. Mreisimactllatlis Sauss. — Crassus et brevis ; tenuiter 

 punctatus ; clypeo flavo, 9 truncato, £ bidentato; thorace brevi, 

 quadrato ; metanoti foveola acutissime marginata, utrinqne et superne 

 angulos dentiformes efficiente; macula ■ front ali et post-oculari, fascia in 

 scapo antennarum, pronoti limbo late, tegnlis, scutello, post-scutello 

 macula subalari et utrinqne metatboracis pedibnsque, flavis; abdomine 

 lato, conico, segmentorum margine punctato, late flavo-liinbato, secundo 

 ssepius utrinque macula flava ; j^rimi fascia utrinqne antrorsum dilatata. 



Odynerus birenimaculatus Sauss. Vespides, I, 135, 16, 9> var - 



Total length, 14 mm. ; wing, 11 mm. 



9. Large and very stubbed. Form very short and very wide. 

 Clypeus wider than long, truncate, finely punctured. Thorax 

 stout, very wide, cubical, a little longer than wide. Prothorax 

 not angular ; mesothorax marked posteriorly with two profound 

 grooves. Post-scutel short, truncate, having a sort of ridge, 

 blunted in the middle. Metathorax very wide; its posterior 

 plate wide, quite flat, finely shagreened, very angulate, and 

 bordered all around by some very trenchant ridges, which form 

 on each side a spiniform angle and on the summit two sharp 

 teeth. Head and thorax very densely and finely punctured. 



