Aculeate Hymenoptera in the Oxford Museum. 381 



Masaris. Thorax broad and rounded coarsely punctured, the 

 prothorax vertically truncate anteriorly, the pronotum margined in 

 front ; mesonotum convex ; scutellum and postscutellum raised 

 gibbous separated from the mesonotum in front from each other 

 and from the median segment by well-marked sutures ; median 

 segment very short somewhat suppressed under the scutellum and 

 postscutellum, the sides rounded not produced posteriorly. Wings 

 ample, the 2nd cubital cell of the forewing petiolate ; legs stout 

 pubescent, claws unidentate. Abdomen sessile the 1st segment 

 somewhat compressed and campanulate posteriorly, 2nd segment 

 long broadening gradually from front to back. 



Length(J 12 mm. (to apex of 2nd abdominal segment). Exp. 27 mm. 



Described from four examples. 



This remarkable and handsome species may afterwards 

 have to be separated generically. I have seen only four 

 males, and they are strikingly aberrant, differing from all 

 known wasps, fossorial or social, in having oyily 9 joints in 

 the antennae. The closest scrutiny under a microscope 

 reveals no more than 9 joints, the apical joint being 

 exceedingly small and sunk in the apex of the subapical 

 joint. 



There can be no question of the insect belonging to the 

 Dijjlojitera ; and in the rest of its structure, particularly in 

 the venation of the forewing, it closely resembles Alastor, 

 under which genus I have provisionally placed it. 



ANTHOPHILA. 



Faviily COLLETIDAE. 



Prosopis simplex, form n. 



Cape Colony : Queen's Park, East London : Sept. 26, 

 1905 {G. B. Longstaff). 



9 . Black immaculate, the tibiae and tarsi turning to slightly 

 reddish brown, the flagellum of the antennae except the basal joint, 

 beneath maroon. Head and thorax closely but not very coarsely punc- 

 tured, the abdomen smooth and slightly shining in certain lights, but 

 not polished. Head broader than the thorax, flat in front, clypeus 

 large, broad, anteriorly truncate antennae short, robust, their apices 

 roundly blunt. Thorax : pronotum transverse, forming a mere narrow 

 ridge ; mesonotum convex with an anterior medial and a lateral, 

 impressed, short longitudinal line which are short and shining ; 



