Itymcnoptcra aculcata 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 : — 



The twenty-first insect was the only specimen of 

 Epcolus produckis ($) 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 Sphccodcs 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 fouiid 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. Q^Q suggests the following 

 conclusions : — 



(1) Sphecodcs rcticulahcs 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 Sphccodes, 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 



