1399.] 



Ill 



but closely allied, species. Que of these is tlie Cmhro ce;phaIotcs o£ 

 Shuckard, Smith, and Saunders, in their works on British Hijmeno- 

 pfera, the other is probably the Crabro planifrons^ of Thomson, = 

 C. sexcinctus, Wesm. Whether the latter is identical with the C. 

 seoecinctus of Fabricius could hardly be determined without a careful 

 examination of the type. The Crabro sexcinctus of Smith and Shucli- 

 ard, is certainly only a variety of the (^ or C. cephalotes, having a 

 silvery instead of a golden pilosity on the clypeus, and I have myself 

 several times met with this variety. It may be remarked that Wesmael, 

 in his critical comparison of the (^ of ceplialotes and G-cmcius makes 

 no mention of the curved hairs which spring from the apex of the 

 basal tooth of the antennse of the latter, nor yet does Thomson in his 

 description of C. planifrons., although this is certainly one of the most 

 distinctive characters of the species. Nevertheless, I suspect that 

 the British insect is identical with this species, and may be dis- 

 tinguished readily from C. ceplialotes by the following characters : — 



C. CEPHALOTES. 



$ . Distance between the first (basal) 

 and second tooth of the antenna 

 greaterthan that between the second 

 and third. Between the first and 

 second tootli tliere is a slight angu- 

 lar production (or minute tooth). 

 This is best seen when the antenna 

 is viewed fi-om above. 



First tooth without hairs. 



? . The 4-dentatc apical margin of the 

 clypeus with the outer tooth on each 

 side not more remote from the 

 nearest inner one than the two 

 inner ones are from one another. 



$ 9 . Basal segment of the abdomen 

 towards the apes decidedly less 

 closely and regularly punctured. 



Abdomen less black, the yellow bands, 

 tliough generally more interrupted, 

 being wider. 



Face viewed from in front less wide 

 across the eyes. 



(J . Mandibles black, rarely with a yel- 

 low spot. 



C. PLANIFEONS. 



Distance between first and second 

 tooth of antennae equal to that be- 

 tween second and third. The arch 

 between the first and second tooth 

 regular, not interrupted by a minute 

 tooth in the middle. 



First tooth with some long curved 

 hairs at the apex. 



? . The 4-dentate apical margin of cly- 

 peus with the outer tooth on each 

 side much more distant from the 

 nearest inner one than the two in- 

 ner ones are from one another. 



(? $ . Basal abdominal segment towards 

 apex very densely and regulai-ly 

 punctured. 



Abdomen blacker, the yellow bands 

 being narrower, generally entire in 

 the ? . 



Face much wider aci'oss the eyes in 

 proportion to its height. 



$ . Mandibles largely yellow. 



