British Hijmenoptera. 255 



extremity. Legs clothed with pale hairs ; tarsi tes- 

 taceous. 



2 . Face densely clothed with black hairs. Clypeus 

 strongly punctured, its anterior margin smooth, rather 

 reflexed, and slightly produced at the lateral angles. 

 Antennae with the 3rd joint longer than the 4th and 5th 

 together ; 6th slightly longer than 5th ; 5th slightly longer 

 than 4th. Thorax densely covered with bright fulvous- 

 brown hairs. Abdomen with fulvous hairs on the 1st seg- 

 ment and on the disk of the 2nd ; the rest of the abdomen 

 above and below clothed with black hairs ; 6th segment 

 with its dorsal valve punctured, triangularly raised in 

 the middle. Legs clothed with dark brown hairs ; pos- 

 terior femora, floccus, and scopes beneath with pale hairs. 

 Length 9 — 11 mm. 



Hah. A common species in April and May. 



I have followed Smith, 1st edition 'Brit. Bees,' in my 

 selection of a <? for this species. In the 2nd edition he 

 has reversed the views he held there, but I find that 

 Schenck and Dours both agree with him in his former 

 identification, and give the smaller-headed <? with the 

 basal tooth to the mandibles to varians. Thomson, on 

 the other hand, gives it to helvola, making a third 

 species, angulosa. My own firm belief is that they are 

 all varieties of one species, and, if Smith's observations 

 are correct, they quite bear out this view, as in his 1st 

 edition he says that he describes from a pair of varians 

 taken in coitu, giving the ^ here described to varians ; in 

 the 2nd edition he exactly reverses the males, and yet he 

 again observes that he is contrasting males that he has 

 taken iii coitu. 



23. Andrena helvola, Linn. 



Linn., Syst. Nat., ed. x., vol. i., p. 575 ; Smith, Cat. 

 Brit. Hym., 2nd ed., p. 42. 



Whether this is distinct from the preceding or not has 

 been more or less a question with most authors. The 

 males certainly are different in appearance, but they are 

 different only in characters which might be the result of 

 development, the ? only in colour. Such characters as 

 I am able to detect I give below. 



$ . Differs from that of varians in the larger, more 

 quadrate, vertex of the head, the lateral angles of which 



