136 HYMENOPTERA OF AMERICA. [lART I. 



a point behind the summit of each eye, two spots or an incomplete 



border on prothorax, a spot under the wing and two on meta- 

 thorax, pale yellow; first abdominal segment ornamented with a 

 border of the same color, interrupted in the middle and extending 

 along the sides; the 2d and 3d having their border brownish, the 

 2d beyond being ornamented with a pale yellow border, inter- 

 rupted and submarginal. Coxae 2d and 3d spotted with yellow; 

 anterior tibiae and tarsi varied with ferruginous; the hair of the 

 legs a little golden. Wings brown, with violet reflections. 



Bess. a. diff. — This 3Ionobia differs from M. angulosa by its 

 clypeus, which presents a flat surface, bordered by two little 

 arcuate, convergent ridges, which end in meeting the two denti- 

 form terminal angles of the clypeus, which approach nearer than 

 with the M. angulosa, where the ridges are straight ; 2d, by 

 the deeper concavity of the metathorax ; 3d, by the structure of 

 the border of segments 2, 3, of which one sees no trace in the 

 M. angulosa. 



Hob. The torrid parts of Mexico. 



S. M. lligripeililis n. sp. — Valida, nigra, valde cribrata ; cljpeo J 

 apiee bideutato, fulvo-rnarginato ; metanoto rugoso, bideutato, loveola 

 punctata, sed liaud acute inargiuata instructo, alis nigris. 



Total length, 20 mm. ; wing, 15 mm. 



9. Large. Appearance of a Rhynchium. Clypeus pyriform, 

 convex, cribrose with coarse pits, terminated by two dentiform 

 angles. Head and thorax densely and coarsely cribrose ; back 

 convex ; anterior margin of prothorax crested ; post-scutel punc- 

 tured above; its posterior face coinciding with the truncation of 

 the metathorax. This last rugose ; its concavity distinct, punc- 

 tured, but not inclosed; its upper edges effaced by the rugosities; 

 on each side is a spiniform tooth. Abdomen conical, very densely 

 punctured, velvety ; the first segment nearly as wide as the second, 

 anteriorly truncate, but not presenting any distinct edge; the 2d 

 moderately long; those following not being more strongly punc- 

 tured. 



Insect entirely black, velvety: its hairs black; the feet only a 

 little grayish ; a spot on upper part of mandibles and a line along 

 the latero-inferior borders of clypeus, tawny. Wings black, their 

 terminal border only, a little whitish. 



Bess. a. diff. — This insect much resembles the Monobia api- 



