EXPEDITION TO SOKOTRA: NEW SPECIES. 15 
abdomen with hair on the base and sides of the first segment, and a band 
of hair at the extremity of the four following segments, of the same colour. 
Legs red, clothed with very long tawny hair ; femora black nearly to the 
extremity, with the cultrate edge beneath the four hind femora bright red. 
Fore-wings clouded hyaline, yellowish towards the base, and iridescent violet 
beyond the middle. 
Sokotra: Adho Dimellus (3500 ft. 18. II. 99) ; two specimens. 
Tiphia, Fabricius. 
(4) Tiphia crassinervis. A 
Long. corp. 14 mm. ; long. al. ant. 9 mm. 
#emale. Black, shining, thickly and closely punctured, abdomen with 
long, fine, outstanding whitish pubescence ; antennze, and tibi and tarsi red 
or reddish, wings smoky hyaline, the nervures black, very thick. Median 
segment with three longitudinal carine, expanding in front, the space be- 
tween smooth; the apex is vertically truncated. Basal segment of the 
abdomen rounded in front, scarcely constricted behind. 
Sokotra : Adho Dimellus (3500 ft., 4-8. II. 99) ; three specimens ; Homhil 
(1500 ft.), E. Sokotra, 25. I. 99 ; one specimen. 
Very distinct from any other species before me, by the incrassation of 
the nervures. 
Sphegidez. 
Sphex, Linn. 
(5) Sphex erebus. 
Long. corp. 20-25 mm. ; long. al. ant. 14-17 mm. 
Deep black; face, from above the antenne to the extremity of the 
clypeus, clothed with white hair slightly tinged with yellow ; clypeus long, 
with parallel sides, or, if anything, slightly narrowed at the lower extremity ; 
hair on the head above and behind and on the thorax, petiole and coxe 
black ; thorax finely and uniformly punctured, scutellum notched in the 
middle, postscutellum with two smooth and shining prominences above, with 
a groove between, median segments transversely striated ; legs black, the 
middle and hind femora and tibize more or less red, wings hyaline, black at 
the base, and dusky at the tips. 
Sokotra: Hadibu Plain, 11-13. XII. 98 ; five specimens. 
Pseudapis. Gen. nov. 
Head as broad as the thorax. Antenne with the 2nd joint transverse, 
3rd shorter than the following ones, which are about twice as long as broad 
till towards the extremity. Eyes converging beneath, ocelli on the vertex, 
the two hinder ocelli about opposite the hinder part of the eyes, and about as 
wide apart as each is distant from the eye ; central ocellus placed just in 
front of the others. Pronotum linear; median segment short, rounded, 
slightly depressed in the middle in front. Tegule enormous, extending 
before and behind the bases of the wings. Legs moderately long and slender 
and clothed with a fine pile ; four front tibiz spined at the extremity ; hind 
tibie ending in the male in a huge broad cultrate appendage ; in the female 
unarmed. ‘Tarsi long and slender, all the joints spined beneath, except, 
perhaps, the front tarsi in the female; first joint of tarsi as long as the 
