1902.] 171 



THE CONCEALED VENTRAL SEGMENTS AND GENITAL ARMATURE 

 OF ANDRENA FEROX, Smitit, $ . 



BY THE REV. F. D. MORICE, M.A., F.E.S. 



I have long wished, but had almost ceased to hope, for an oppor- 

 tunity of dissecting the above extraordinarily rare bee, in order to 

 compare its "armature," &c, with those of the other species of 

 Andrena which I have examined. At last, through the kindness of 

 Mr. A. J. Chitty, such an opportunity has been given me. He has 

 been good enough to let me extract the parts in question from an 

 almost fresh specimen taken by himself near Faversham ; and although 

 the result has a little disappointed me, I think it is very desirable to 

 record it. 



I had expected something decidedly abnormal in the interior 

 structure of a species whose external characters are so striking and 

 singular. Both the genitalia (stipites and sagittae) and the Sth ventral 

 segment of the somewhat similar A. bucephaht, Sm., are highly para- 

 doxical, and I had thought it likely that those oi ferox would be even 

 more so. 



On the contrary, they prove to be particularly simple! They 

 resemble very closely those of A. roses. The armature is a little 

 broader and rounder as a whole, but the details of its structure are 

 closely analogous in the two species. The 8th ventral segments also 

 are very alike ; only m ferox the apex is scarcely bifid, while in rosea 

 var. Trimmerana it is very strongly so ; and though the character is 

 less conspicuous in var. spinigera (which, \We ferox, has a large head, 

 a spined gena, and a rufescent abdomen) it is at least distinctly in- 

 dicated. The 7th ventral segment in ferox again recalls that of rosce ; 

 the " teeth " at its apex, however, seem rather more parallel and sepa- 

 rated by a wider notch, but the difference is so slight that (with only 

 one specimen of ferox before me) I should hesitate to lay much stress 

 upon it. 



Another large headed (non-British) species much resembles ferox 

 in the points of structure mentioned above ; this is megdcephala, 

 Smith, a species whose male has a strong external similarity to buce- 

 phala, agreeing with it, and differing h'oxw ferox, in having the genre 

 simple. 



If I am right in thinking that the characters of the armature 

 and the concealed ventral segments in Andrena . species ought to be 

 seriously considered in attempting to arrange the latter in groups, it 

 would seem that ferox, meqacepltala, and roses (together with various 

 forms which continental authors generally separate from the latter, 



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