Hymenoptera aculeata collected in Algeria: the Sphegidae. 125 
black spot. On the thorax the collar, tegulae, and 
humeral tubercles alone show any trace of yellow. 
SPHECIUS HEMIXANTHOPTERUS, Nh. Sp. 
3 f$fand 19. Biskra, 27. v-9. vi, 98. F. D. M. 
This and the next species agree in most structural 
characters, and also in certain details of coloration which 
seem to be constant in both sexes, and which do not seem 
to characterise any of the species yet described from 
Palaearctic localities. The yellow fasciae of the abdomen 
above, which (as in wljanini, Rad.) are extremely wide 
and almost or quite continuous on all the segments, are 
ornamented with a series of little oval spots or specks 
(black in the ¢ 4%, reddish in the $$) on segments 2-5. 
The spots stand out conspicuously in the middle of the 
yellow spaces surrounding them. On each segment there 
are two of them, one on each side. On segment 1 they 
are wanting, but instead—at the same distance from the 
sides of the segment—the basal margin of the yellow 
fasciae is interrupted by a little punctiform or linear 
incision, as though the blackness or redness at the extreme 
(declivous) base of the segment had just a little “ over- 
flowed” on to its yellow disc. The phenomenon is so 
similar in both species, that at first I did not doubt they 
were identical; but the characters given below make me 
certain that they should be distinguished. (Cf. the 
description following of claripennis, n. sp.) 
The 2 of hemixanthopterus is extraordinarily like that 
of uwljanini as figured by Radoszkowsky, and redescribed 
from the type by Handlirsch; but the character just men- 
tioned does not seem to occur in wljanini, and there are 
other differences which I shall note below. Uljanini f is 
unknown. 
Species in utroque sexu singularis alarum discis brunnea quadam 
flavedine infuscatis quae cellulam radialem, cubitalesque 1™™ et 
2"“"non autem 3"*™ !—occupat. 
¢. Antennarum fulvescentium articuli 2 penultimi basisque 
ultimi subinfuscata : artic. ultimus in medio fortiter ut in nigricorni 
semel flexus (infra haud bisinuatus !). Metatarsi intermedii ut in 
antennato (non ut in nigricorni). . 
Pictura opulenta. Flava sunt facies tota sub antennis cum 
oculornm orbitis interioribus latis: mandibulae (exceptis apicibus 
nigris) ; collaris margo posticus : mesonoti latera cum tegulis tuber- 
