220 HYMENOPTEEA. » 



than long, and semilunate ; the scutellum has its sides yellow throughout, and has a 

 black mark in the centre at the base ; the top of the yellow marks on the metanotum 

 is tongue-shaped, not triangular ; the sides of the petiole are black, and there is a large 

 black mark on the outer, and a smaller and broader one on the inner, side of the hind 

 coxae, the two being quite distinct. Structurally it differs in having the antennae 

 longer, the petiole broader, the tubercle at the side of the postpetiole much more distinct, 

 and the abdomen shorter and much broader, the latter being (not counting the petiole) 

 of the length of the head and thorax together, while that of M. lamentarius is consi- 

 derably longer than that. The sculpture is nearly the same in both species. 



16. Mesostenus acceptus. 



Mesostenus acceptus, Cresson, Proc. Acad. Phil. 1873, p. 154 ( $ )\ 

 Hob. Mexico, Orizaba 1 (Sumichrast). 



17. Mesostenus veraepacis. 



Had. Guatemala, Panzos in Vera Paz (Champion). 



Similar in size and coloration to M. lamentarius, except that the mesosternum is 

 black, the mandibles yellow at the base, and the yellow marks on the metanotum are 

 tongue-shaped, not triangular, above the tubercles ; differing otherwise from that species 

 in the base of the metanotum not being so strongly punctured, the petiole not furrowed 

 in the centre, the abdomen broader, the ovipositor a little shorter, the hind coxae with 

 only one large black mark on the outer side (not two joined at the apex), and the meta- 

 thoracic tubercles shorter, thicker, and not curved. 



18. Mesostenus fraternans. 



Niger, flavo-maculatus ; facie, orbitis coxisque anterioribus, flavis ; pedibus fulvis. $ . 

 Long. 17-18 millim. ; terebra 9*5 millim. 



Hab. Mexico, Presidio (Forrer). 



Antennae stout, about as long as the body ; the scape in the middle beneath, and a 

 broad ring on the flagellum, yellow. Head punctured, the face projecting in the middle ; 

 mandibles black. Pro- and mesothorax punctured, the sides longitudinally striated ; 

 middle lobe of the mesonotum clearly denned by the furrows ; scutellum longer than 

 broad, punctured. The metanotum is shining, and punctured above the transverse keel, 

 below it coarsely, transversely striated; the pleurae are coarsely and longitudinally 

 striated ; the tubercles broad, hollowed on the outer side, punctured. The prosternum 

 a broad line on the edge of the pronotum, the tegulae, the tubercles beneath them, the 

 greater part of the mesopleurae, a large mark under the hind wings, a large oblique 

 mark on the metapleurae, a mark at the apex of the middle lobe of the mesonotum, the 

 scutellar carinae, the scutellum, the postscutellum, and two longish marks on either side 



