CRABRO TIBIALIS. 123 



centre is a slight channel ; beyond the smooth space is a deep 

 central fovea, with a line emanating from it which runs to the 

 apex ; the sides covered with white silky pubescence ; the tu- 

 bercles yellow-testaceous ; the tegulae testaceous ; the wings 

 hyaline and iridescent, the nervures piceous ; the anterior and 

 intermediate legs yellow, with the base of the femora and a 

 stain inside the intermediate tibiae piceous ; the posterior legs 

 dark rufo- piceous, with the apex of their coxae and the base of 

 the tibiae yellow ; the intermediate and posterior tibiae spinose. 

 Abdomen ferruginous, with the petiole and the base of the 

 first segment black ; the fifth segment usually piceous ; some- 

 times the third segment only ferruginous, and all the margins 

 piceous. 



Male. Rather smaller, and differing in having the sixth joint of 

 the antennae emarginate beneath ; the joints rufo-piceous, all 

 coloured above, and two or three of the apical ones entirely so. 



This species is generally distributed. It burrows in decaying 

 wood, from which I have several times bred it ; it also perforates 

 bramble-sticks, as do many species of this genus : by collecting 

 perforated sticks in the spring, many of the small fossorial 

 insects may be obtained. 



2. Crabro tibialis. 



C. niger ; abdomine petiolato, primo segmento nodoso ; tibiarum 

 posticarum apice rufo. 



Crabro tibialis, Fair. Ent. Syst. Supp. 271. 27-8. 



Panz. Faun. Germ. 83. 14. 



Van d. Lind. Obs. ii. 73. 35. 



Shuck. Foss. Hym. 177. 34. 



Zett. Ins. Lapp. 442. 



Pemphredon tibialis, Fabr. Syst. Piez. 315. 4. 

 Corynopus tibialis, St. Farg. Ann. Soc. Ent. Fr. in. 803. 1 (1834); 



Hym. iii. 205. 1. 

 Rhopalum tibiale, Westw. Mod. Class. Ins. Gen. Synop. 80. 



Dahlb. Hym. Europ. i. 288. 177. 



Curtis, Brit. Ent. xiv. t. 656 <? . 



Wesm. Hym. Foss. Belg. 127. 3. 



Female. Length 2|-3 lines. Black; head wider than the thorax, 

 very smooth and shining, the face delicately punctured ; a 

 smooth depression at the side of each of the posterior stemmata ; 

 the scape fulvous at the base and apex beneath ; the clypeus 

 produced in the centre, projecting in front, and covered with 



G 2 



