- 
64 Rev. F. D. Morice on 
followed Herr Kohl’s work (“Sphegiden-Gattungen,” Wien, 
1896). (4) Practically the entire treatment of certain 
Genera, which had been left to me by our arrangement, 
especially Ammophila, Cerceris, and the Genera included 
in various works of Kohl and Handlirsch, e.g. Diodontus, 
Nysson, Sphecius, Stizus, ete. (But I should add that I 
have rarely arrived at a determination of any doubtful 
form even in these Genera without at some time consulting 
Saunders on the subject, so that many of the determina- 
tions were really rather his than mine.) 
My whole collection of Crabro (sensu latiore) has been 
recently examined and determined for me by Herr Kohl; 
and, as will be seen below, some also of the names here 
given for specimens in Saunders’s collection rest on his 
authority. The same great hymenopterist has at various 
times given me or named for me examples of a great 
many little-known Mediterranean Sphegidae; and having 
these “quasi-types,” as they may be called, before me, I 
have been enabled to arrive at determinations, which I 
hope are correct, of several specimens left unnamed by 
Saunders. Whenever I have ventured to question any of 
my colleague’s identifications, it has nearly always been 
on the authority of some specimen of my own determined 
by Kohl, Handlirsch, or Schletterer. 
I have thought it right to enter into the above details, 
which might otherwise seem rather tedious, because I am 
anxious not to claim for myself the credit for work which 
is really that of my friend, and yet not to cast upon him 
the responsibility for imperfections arising simply from 
the fact that I, and not he, have put this work into its 
final shape. 
On a rough calculation it appears that very nearly 200 
Sphegidae-spp. belonging to 33 genera are recorded below. 
Of these, more than half occurred at Biskra only (!); and 
that half comprises nearly all the finest and most striking 
forms, and quite a surprising number of species and even 
genera (Kohlia, Laphyragogus, etc.) which were either 
altogether or almost unknown to science when we found 
them. Several of these almost tropical insects occur 
also in Egypt, on the border-line between the Delta 
and the deserts east and west of Cairo, and, together 
with the species most nearly related to them in the same 
districts, appear to form a definite “Saharan” group; which 
probably extends all along the northern fringe of Central 
