British Hijmcnoptera. 233 



2 and 5 . Like tlie $ in colour, though generally darker ; the 

 abdomen without black hairs ; the 2nd, 3rd, and 4th segments with 

 a basal baud of brighter and darker brown hairs ; corbicula of pos- 

 terior legs with pale hairs; beneath clothed with pale hairs. 

 Length, 10 — 18 mm. 



Hah. Not uncommon in mcany places, and generally 

 distributed. 



This species, called by Dr. Schmiedeknecht variabilis, 

 is the true cognatus, Stephens, of which I have had the 

 opportunity of examining the type in the British Museum. 

 In this country I do not think it varies to the extent that 

 it does on the Continent. Some old specimens, long 

 exposed to the weather, are nearly grey, and some dark 

 varieties of the ? and ^ are brown, not yellow ; but I 

 have never seen anything like the very dark varieties 

 mentioned by Schmiedeknecht. It is at once known 

 from Smithianus by the pale under side, &c. ; from 

 muscorum by the characters gi^en in the note to that 

 species. 



3. Bomhiis muscorum, Linn. (PL XII., fig. 7). 



Linn., Syst. Nat., ed. x., i., p. 579 ; Smith, Cat. Brit. 

 Hym., 2nd ed., p. 199 = agrorum, Schmied., &c. 



Thorax clothed with tawny yellow hairs ; abdomen with yellow 

 hairs, mere or less mixed with black, sometimes almost entirely 

 black ; legs clothed with black hairs ; underside with pale cchreous; 

 antennae of the ^^ with each joint of the flagellum produced and 

 rounded on its anterior margin. 



J . Head clothed with black hairs, intermixed in some varieties 

 with paler ones, especially on the face ; cheeks shining, rather 

 longer than their apex is wide. Antennae with the 3rd joint of the 

 flagellum considerably shorter than the 2nd, its 4th and following 

 joints produced and rounded on their anterior margin. Thorax 

 densely clothed with tawny yellow hairs, in seme varieties with a 

 few black haii's intermixed. Abdomen clothed with tawny or 

 ochi-etus hairs, more or less intermixed with black (in some 

 varieties the black appears only on the sides of the 1st and 2nd 

 segments, in others the black hairs extend nearly all over the 

 segments, leaving only a paler cchreous fringe at the apex of each) ; 

 beneath clothed with greyish hairs ; genital armature with the 

 squama deeply emarginate on its inner margin, and with an ajjical 

 semewhat rounded production beyond the emarginatien ; at the 

 base of the squama is a short spine projecting forwards ; lacinia 



