Hymenoptera aculeata from Majorca and Spain. 645 
included in the numbers given in the present memoir. 
Separated out from other captures of the same species 
the list is as follows :— 
Sphecodes fuscipennis . Prk es 
5 grbbus oe eg teen ee cl 
% subquadratus . . 72 
7 reticulatus ee 
Fs rufiventris ie 
The mimetic fly— 
Ocyptera brevicornis . . . I 
20. 
The twenty-first insect was the only specimen of 
Epeolus productus (?) in the material described in this 
paper. 
The whole of the captures made by the three naturalists 
on that sunny afternoon by San Geronimo afford the material 
for a much larger group, including far greater numbers 
of the same species of Sphecodes and some additional species 
of Aculeates with the same general appearance. This com- 
plete group is shown below. In the right-hand column 
will be found a record of all other captures of the con- 
stituent species in Spain during the same expedition (1901). 
A glance at the table on p. 646 suggests the following 
conclusions :— 
(1) Sphecodes reticulatus was the dominant species on 
July 15, while three out of the five species of Sphecodes 
were far more abundant than any other members of the 
entire group. 
(2) There was an evident special association of the 
species of the group in the locality at San Geronimo, A 
large proportion of them were not taken elsewhere. 
(3) The elevation had obviously delayed the emergence 
of the species of Sphecodes, so that hardly any females had 
as yet appeared. The proportion of the sexes only 1000 
feet lower was very different. 
Mr. Edward Saunders tells me that “ with few exceptions 
the males of Sphecodes precede the females by a week or 
so. In the autumn when both are out the females are 
found more round the burrows and not so much on the 
flowers as in the spring. The new females hibernate and 
the males die off.” 
(4) It is probable that the stingless males of Aculeates 
