Four of the Bombi were formed into a subdivision by Mr. 

 Kirby in his Monograph, and they have been lately designated 

 as the genus Psithyrus, Avhich I think might as well have been 

 called Bremus, a name given to the Bombi by Jurine. 



The males are distinguished from the Bombi by the nearly 

 equal breadth of the posterior tibiae, which are externally con- 

 vex and thickly clothed with hairs, whereas in Bombus they 

 increase from the base to the apex, are slightly concave ex- 

 ternally at the centre, and have only scattered hairs ; the 

 females are still more strongly marked, having in addition to 

 the above characters, a trigonate labrum and mandibles not 

 toothed. 



The following are our British species : 

 1. P. rupestris Fab. — Curt. Brit. Ent. pi. 468. represents the 

 female a little larger than life. — arenaria Pz. 74. 12. 

 var. The male is unknown unless it be the P.frute- 

 torum. 



End of June, several on a thistle, near Drayton Norfolk, and 

 Wrentham Suffolk, also by the road-side, and flying about a 

 hay-stack in Cambridgeshire ; middle of August, on a common 

 near Coombe, Mr. R. Lewis ; beginning of September and 

 middle of October, Isle of Wight, J. C. ; near Axbridge and 

 Glanville's Wootton, Mr. Dale. 

 '2. P. frutetorum Pz. 75. 20. — Albinellus Kir. v. 2. p. 361. 



Beginning and middle of August, on thistles, Richmond 

 Park, once with P. rupestris, Mr. R. Lewis : at Barham, in 

 the autumn, Mr. Kirby. 



3. P. Rossiellus K. tab. 18. f. 1 $ .—^chcef. Icon. t. 241./7&8. 



The male only of this Insect is known, but probably 

 P. campestris may be the female. 

 Barham, in flowers : middle of July, Dover, J. C. ; middle 

 of August, Coombe Wood, on thistles, Mr. Lewis. 



4. P. campestris Pz. 74. \\. — Kir. 1. 18./. 2 ? . 



Barham, in spring and summer; June and July, near Brix- 

 ton Hill and Coombe, Mr. Lewis ; Shanklin Chine, Mr. Dale. 



5. P. Barbutellus Don. v. 11. ;?/. 385. f. 3.— saltuum Pz. 75. 



21 J? — autumnalis Fab. S var. 

 Barham, flowers in summer ; male frequent on thistles : mid- 

 dle of May, Hampstead; end of June, Darent; common in 

 Battersea Fields. 



6. P. vestalis Four.— Kir. /f. 18. /. 3 &4 ? & S ■ — Don. 13. 



;pZ. 464 — aestivalis Pz. 89. 16. 

 Barham, flowers of Tussilago Farfara (pi. 367), often flying 

 close to die ground. Mr. Lewis finds it in Coombe Wood 

 lane about May. 



The Plant is Digitalis purpurea (Purple Foxglove). 



