60 Rev. F. D. Morice on mah terminal spgmenU and 



heather in late summer, but in Egypt I have taken it 

 quite early in the year — on what plants I cannot re- 

 member, but certainly not on heather. 



31. Irivimndatus, Nyl. PI. VIII, 31, 31a. 



I feel no doubt that the insect from which I figure 

 belongs to Nylander's species, nor that alpinus, Morawitz, 

 is a synonym of the same. All my examples are from the 

 Alps, where it is tolerably common. 



The seventh ventral plate is most peculiar, and alone 

 would distinguish the species at a glance. If we imagine 

 the hairy transverse lobes of 2i fo'ifjidus contracted into a 

 more quadrate shape, and furnished each at its inner apical 

 corner with a long horn or tail of exceedingly thin trans- 

 parent membrane, we should get the condition which we 

 actually find in imjmncfahts. The armature is much more 

 ordinary. Its stipites are formed nearly as in iriontanus, 

 but the sagittse have only a single basal dilatation ; and 

 their " wings " either arc narrower, or are so folded as to 

 hole so, with a pointed rather than a rounded apex — but 

 this last I take to be mainly an effect of " foreshortening." 



No other Colldes — unless ^o&&\h\y pumilus — has a seventh 

 ventral plate with anything even remotely approximating 

 to the apical tails of imjmnctatus, and in that species both 

 the armature and the external characters are altogether 

 different. If iiwjjunctatus has really special affinities with 

 any other Colletes-species, it perhaps comes as near to 

 frigidus as to any ; but I should be more inclined to place 

 it in a special group of its own. 



32. Acutus, Perez. PI. VIII, 32, 32a. PI. IX, 43, 43«. 



I have two males and two females of this very distinct 

 species, all from Algeria. 



The seventh ventral plate seems to me to exhibit in a 

 rudimentary form the paradoxical modifications which 

 become stronger and stronger in the species which follow. 

 The interior " costas " are detaching themselves from the 

 " lobes " to stand up as separate spike-like processes, and 

 the commencement of a similar change seems indicated 

 by the sharp sinuation — almost an incision — near each 

 outer extremity of the apical margin. 



In the armature I see nothing to call for special atten- 

 tion, except the very large and conspicuous volsella. 



