ON SOME NEW CENTRAL AMERICAN VESPID^. 81 



Clypeus broad, sparsely, weakly punctured; its apex broadly rouuded, 

 with a short, stout tooth on the sides of the middle third. There is a 

 large, rounded apical tooth and a short, much less distinct apical one 

 on the mandibles. Base of thorax transverse, raised into a thin, pale 

 horny projection, which is continued along the basal half of the pro- 

 pleuras, below the top ; the apex bluntly rounded laterally, the centre 

 rather flat, the middle with a narrow furrow ; except in the centre it 

 is closely, strongly, more or less obliquely striated. Front and vertex 

 strongly, closely punctured ; the ocelli in a triangle ; the mesonotum 

 is less closely punctured and the scutellum still less closely punctured; 

 the post-scutellum smooth, punctured at the base. Pro- and meso- 

 pleurse strongly punctured, the metapleurte smooth, except for some 

 fine obscure striae above and along the apex. 



This is a Didymogastra. The last joints of the antennae 

 can neither be called "a rolled spiral" nor a "hook," but the 

 appendage approaches in form more the latter than the former. 



Zethus nitidinodus, sp. nov. 

 Black ; a broad curved band on the apex of the clypeus, its upper 

 edge irregular, a small spot above each antenna, a small one on the 

 outer orbits above, a line on the sides of post-scutellum, about three 

 times longer than wide, a mark, wider than long, narrowed on the 

 inner side, on the sides of pronotum, a conical mark, obliquely nar- 

 rowed above, below the tegulre, and two large, irregularly pyriform 

 marks, dilated below and with the outer side oblique, straight, on the 

 apex of metanotum, a line on the apex of first abdominal segment, 

 narrowed in the middle and continued backwards on the sides below 

 for about as far as the width of the segment, and a much narrower 

 line on the apex of the second, pale cream-yellow. Abdomen very 

 smooth and shining, the apical segments thickly covered with grey 

 pubescence ; the petiole not so long as the thorax, and not much 

 longer than the second segment ; its basal fourth narrowed, spinose 

 laterally at the base ; the thickened apical part distinctly narrowed at 

 the base, slightly narrowed at the apex, which is depressed. Second 

 segment bell-shaped, the base narrowed into a short neck, about twice 

 longer than wide ; it is about one-fourth longei: than it is wide at the 

 apex, which is neither reflexed nor channelled ; but the third segment 

 is distinctly reflexed. Wings fuscous violaceous, the nervures and 

 stigma black. Antennae with a longish, stout, little curved hook. ^ . 

 Length, 22 mm. 



Mexico. 



Front strongly, closely punctured, the vertex more sparsely and 

 weakly so, its hinder edge smooth. Clypeus sparsely, distinctly 

 punctured, its apex bluntly, shortly bidentate, the sides curved. Ocelli 

 in a curve, the hinder separated from each other by a distinctly less 

 distance than they are from the eyes. Base of thorax above clearly 

 separated, keeled behind, the sides distinct, but not projecting. Parap- 

 sidal furrows distinct, complete. Scutellums smooth, not furrowed, 

 the apex broadly narrowed behind. Depression in centre of meta- 

 notum deep, the lobes broadly rounded. Apical two joints of antennae 

 dark cream-coloured, the hook black, its apex reaching to the base of 



