250 PROCEEDINGS OF THE ACADEMY OF [1897. 



metanotum, rather truncated, above basally obliquely striated, becom- 

 ing granulate posteriorly, while the posterior surface has a spongy 

 or porous appearance : legs scarcely spiuose, claws bifid, the ante- 

 riors with the inner part short, (hind claws missing) ; abdomen 

 elongate-ovate, with sparse, black hairs beneath, sixth ventral at 

 apex with a strong medial emargination on each side of which is a 

 strong tooth, seventh ventral slightly keeled down middle, its upper 

 surface, which is visible from above, bounded by a prominent mar- 

 gin or reflexion ; wings broad, dark bluish and purple. Length 

 18 mm. 



Chapada (April). One specimen. This is a remarkable Pompilus 

 in the shape of head, sculpture, elevated postscutellum and broad 

 wings. It comes nearly to that group of species of which pygidia lis 

 Kohl and fervidus Smith, are types. The venation of wings : an 

 unusually long marginal cell ; basal vein originating before apex of 

 submedian cell ; cubital vein of hind wing originating far before 

 apex of submedian cell. 



Pompilus polistoides Sm. 



Twenty-three specimens of both sexes. Chapada (March, April, 

 November, December) ; Corumba and Maruru (April) ; Rio de Jan- 

 eiro (November) ; Santarem. This species varies considerably in 

 size, but the maculatiou is fairly constant. 



Pompilus decedens Sm. 



Santarem. One specimen. 



Pompilus rhomboideus n. sp. PI. IV, f. 11. 



9 . — Black, with a very faint tinge of blue on abdomen ; front, 

 clypeus, coxre and abdomen with cinereous pile ; head with long, 

 black, sparse hairs ; clypeus incurved medially ; front with an im- 

 pressed line ; front closely punctured ; eyes reaching mandibles 

 almost parallel within, separated at the top by a distance nearly 

 equal to length of antennal joints 2 and 3 ; space between hind 

 ocelli equalling a little more than half that which separates them 

 from eyes; first joint of flagellum more than one-third longer than 

 second ; pronotum with large lateral angles tumid, its posterior mar- 

 gin angulate; middle segment broadly rounded, slightly impressed 

 in the middle at base ; legs spiuose, but not strongly, tarsal comb 

 wanting, claws bifid, longer spur or' hind tibia? short, equal to some- 

 what more than one-third the length of first hind tarsal joint ; abdo- 

 men beneath and apically with long, black hairs ; wings dark fuscous 



