of Exotic Hymenoptera. 83 



Genus Liogastba, Perty. 

 1. Liogastra quadriplagiata. 



L. nigen-ima, pilosiiisciila ; abdominis basi plagis quatuor lutescenti-albis 

 ornata; capite supra, tliorace antice et lateraliter albo-pilosis ; alis 

 nigrescentibus A'iolaceo-niicantibus. 



3Iale. Length 9|- lines. Jet-black, and thinlj' sprinkled with pale 

 glittering silky pubescence ; the face as high as the insertion of the 

 antennae, and a liue on each side above them, nearly meeting in front 

 of the ocelli, covered with white pubescence ; the clj^eus widely emar- 

 ginate ; the anterior margin of the labruni rounded ; the antennae rufo- 

 piceous beneath, and with an elevated carina between their insei-tion. 

 Thorax : two transverse spots in front, a larger subovate one beneath 

 the wings, and a line on each side of the metathorax covered with 

 white pubescence ; the scutellum bituberculate ; the wings nigro- 

 fuscous, with a bright violet iridescence. Abdomen : a large ovate 

 macula of white pubescence on each side of the two basal segments. 



Female. This sex differs in ha^'ing• the face black, and the white spots 

 on the thorax nearly obsolete : the spots on the abdomen are much 

 smaller, and the apical segment is pointed ; in the male it is bilobed. 



Hab. Mexico. 



This species was taken by M. Salle ; it is one of the most beautiful 

 of the whole family of Apidae, and is the fourth species discovered of 

 the genus to which it belongs ; the other three are from Brazil. 



ICHNEUMONID^. 



Family Aulacidae, Shuck. 



Genus Tkigonalys, Westiv. 



1. Trigonalys ornata. 



T. nigro-fusca ; capite thoraceque maculis flavis omatis ; abdomine flavo- 

 fasciato ; alis hyalinis ; pedibus flavis. 



Length 5| lines. The head large, wider than the thorax ; the mar- 

 gins roimded, somewhat flattened in fi'ont ; the clypeus transverse, 

 its anterior margin slightly rounded and emarginate ui the middle ; the 

 head, mandibles, and four middle joiuts of the antennte of a sidphur- 

 yellow ; the mandibles ■nath three black teeth ; a minute black, or ratlier 

 a fuscous spot between the anteuna3, a circular broad ring above them 

 extending to the fii'st ocellus and uniting with a subtriangular spot 

 enclosing the posterior ocelli, on each side of which is another cm-ved 

 fuscous stripe, which becomes narrower and unites at the margin of the 

 vertex. The thorax and legs are yellow ; the former has three broad 

 longitudinal stripes on the mesothorax, another on the scutellum and 

 metathorax in the middle, and also a small triangular spot on each 



