172 
Psyche 
[September 
closed submarginal cell and two closed discoidal cells (superficially 
resembling certain pemphredonine Sphecidae) ; hind wing not fully 
visible, but evidently with a strong vein on the basal, anterior mar- 
gin, without closed cells. Legs not spinose; tibial spur formula 
1-2-2; claws dentate. Metasoma slender, sessile, with 7 visible seg- 
ments, without a constriction between first two segments and without 
unusual modifications. 
Type-species. — Cretabythus sibiricus, new species. 
Remarks. — This specimen is reasonably well preserved and nearly 
complete, but it presents a puzzling combination of characters. I 
had at first supposed it was a pemphredonine sphecid related to 
Pittoecus , but despite similarities in the wing venation there are 
several reasons for excluding it from this group : the broad, 4-toothed 
mandibles, pronotal lobes reaching the tegulae, two mid-tibial spurs, 
lack of closed cells in the hind wing, and so forth. The wing vena- 
tion appears closest to that of the Scolebythidae (though unfortu- 
nately one cannot be sure whether the anal lobe is developed) and 
there are other features in common with that group. 2 However, 
there are also several major differences: e.g. lack of a distinct pros- 
ternum and proepimera, presence of an anterior pronotal collar and 
of a transverse carina on the propodeum, and differences in the form 
of the first metasomal segment. It is probable that modern Scole- 
bythidae are specialized for life beneath bark or in holes in wood, 
and the absence of such specializations in Cretabythus should not 
necessarily exclude it from this family. For the present I can suggest 
no better placement for this unusual wasp. 
Cretabythus sibiricus, new species 
Length 2.5 mm; fore wing about 1.9 mm. Fuscous, except pro- 
notum apparently somewhat lighter than remainder of body; legs 
stramineous; antennae stramineous basally, slightly infuscated toward 
apex; wings hyaline, stigma brown, veins light brown. Body with- 
out strong surface sculpturing and without noticeable setae. Anten- 
nal segments in the following ratio : 5 :4 .*5 :5 : 5 :5 :5 :5 :5 :5 :5 :5 :5 ; 
segment three about 1.7 X as long as wide. Segments of front 
tarsus in a ratio of 8 14. :3 :2 :5 ; longer spur of hind tibia 0.4 X 
length of hind basitarsus. 
2 When I described the Scolebythidae (Evans, 1963) I had only females. 
I have since discovered a male Cly stops enella longiventris Kieffer and can 
state that there is no marked sexual dimorphism in this group. The family 
currently has a broadly discontinuous distribution in Brazil, Madagascar, 
and Australia (the Australian element has yet to be described). 
