Families Bethylide and Rhopalosomide. 107 
broad depression ; scutellum with a deep transverse sulcus 
at the base. Median segment nearly half as long again as 
- broad, margined at the sides and at the apex, very finely and 
closely transversely striated, with five longitudinal carine, 
the median one reaching the apex, the two lateral extending 
beyond the middle, the two intermediate not reaching the 
middle ; the sides of the segment and the surface of the apical 
truncation almost smooth. Abdomen shining, the fifth and 
sixth dorsal segments with scattered punctures. Fore wing 
with the medius short, which causes the basal nervure and 
the nervulus to meet at an acute angle, forming two sides of 
an equilateral triangle ; stigma small; radius long. 
Hab. British East Africa, Voi, 1800 ft. (S. A. Neave), 
March 21-23, 1911. 
Family Rhopalosomida. 
Genus Orxon, Cam. 
Olixon, Cam. Biol. Centr.-Amer., Hymen. i. p. 412 (1887). 
Saphobethylus, Kieff. Ann. Soc. Sci. Bruxelles, xxxv. p. 216 (1911). 
Type of the genus, O. testacewm, Cam. 
Saphobethylus pallidus, Kieff., is a synonym of Olixon 
testaceum. 
Cameron places this genus in the Braconide, expressing 
strong doubt as to the true relationship of the genus, and 
noticing a general resemblance to the Bethylide. Kieffer 
places it in the Bethylidz without comment on the abnormal 
characters. ‘The antenne are 13-jointed in the male, 12- 
jointed in the female, very long and slender, agreeing well 
- with Rhopalosoma, with which the genitalia of the male also 
show close affinities. It differs from that genus in the entire 
eyes, in the absence of ocelli, in the rudimentary wings, and 
in the subsessile abdomen. The tarsi of the female do not 
show strongly broadened joints asin Lhopalosoma. Though 
these differences remove Olizon from very close relationship 
with Rhopalosoma, it seems to be sufficiently near to be 
placed in the same family. With regard to the affinities of 
the family, it must be pointed out that the genitalia show 
a very distinct relationship to those of the Eumenide and 
differ strongly from those of all other Hymenoptera. Thus, 
of the many attempts to assign a place to the group, that of 
Westwood, who connects it with the Vespide, is the most 
correct. It is almost certainly derived from the same stock 
as the Eumenide, but strongly modified by nocturnal and 
