examination of the troplii, will frequently lead to error. The 

 group before us was many years since noticed by Mr. Kirby 

 and called Rhopalwn, and other celebrated writers have con- 

 sidered it a distinct type from Crabro, with which Mr. Shuck- 

 ard has united it in his elegant Monograph of the Fossorial 

 Hymenoptera. On a comparison of the tropin however the 

 necessity of separating our two insects from Crahro is manifest : 

 the most obvious differences are the palpi being only 5 and 3- 

 jointed, whilst in Crahro patellatus the maxillary have 6 and 

 the labial 4 joints, and the lip is nearly as long as the labial 

 palpi : I ought to remark that I could not obtain recent spe- 

 cimens for dissection, but I have no reason to think they had 

 been mutilated. Even the two species oi RJio2)alum vary so 

 materially that they must form at least 2 sections ; the antennte 

 of the males and the clypeus are very different, as well as the 

 structure of the tarsi, and the remarkable lobes attached to the 

 abdomen 1 have not yet discovered in R. riifiventre. 



1. tibiale Fah. — Curt. Brit. Ent. pi. 656. (J.— Corynopus 

 .SV. Farg. 



Male black, shining, slightly silky ; clypeus porrected obliquely, silvery, 

 lobed in the centre ; inner margin of eyes silvery ; tropin ochreous, base 

 of mandibles black ; basal joint of antennae yellow beneatli, 2ndsubtrigo- 

 nate produced on the inside, yellow at the apex, 3rd small truncated ob- 

 liquelv, 4th and 5th stout, elongated and somewhat hatchet-shaped, being 

 emarginated beneath, following short, Gth and 7th yellow at the apex, yth 

 and 11th straw colour (1 *) : abdomen with the margin of the 2nd segment 

 sometimes ferruginous, as well as the apex, which is furnished with 2 lan- 

 ceolate laminiE : nervures and stigma piceous : legs yellow ; thighs black, 

 except at the tips, anterior tibiae with a black spot on the outside, the 

 others with a black ring, the hinder dilated and rufous at the apex : tarsi 

 tip])ed with orange, basal joint ciliated externally and dilated in the an- 

 terior, hinder brown, the base and 4th joint subrufous, the former produced 

 externally at the apex. Female larger and stouter ; clypeus acuminated 

 in the centre; antennas simple, 4th joint longer than the 3rd or 5th ; basal 

 joint of tarsi not dilated, 4 anterior tibiae piceous beneath: anus acumi- 

 nated and channelled above. 

 July, Parley, Blandford, and Gl. Wootton, Mr. Dale ; 



Darent, Mr. Shuckard ; on Lime-trees, Southgate, Mr. F. 



Walker; about laurels at Netley, Shropshire, Mr. Westwood. 



2. rufiventre Fab. — Vanz. 72. 12. — Physoscelus ^t. Farg. 

 Shining black ; margins of the 2nd abdominal segment and sides of the 

 3rd ferruginous ; clypeus semicircular and silvery, sides of face silvery ; 

 mandibles yellow, tips ferruginous ; antennae with the basal joint yellow 

 beneath, the following ochreous beneath excepting the apical ones; legs 

 straw colom-, thighs black, except at the apex, intermediate tibice with a 

 dark dot on the inside at the middle, hinder legs piceous, base of tibiae 

 whitish : 2^ lines. Female with the abdomen rufous, excepting the petiole, 

 and sometimes the 2nd, 4th and 5th segments are piceous : 2^ lines. 

 July, Parley, in a garden at Blandford, Gl. Wootton, Mr. 



Dale ; near Hyde, Rev. G. T. Rudd ; in June, Norfolk, and 

 August, Isle ol" Arran, J. C 



The Plant is Caucalis (Torilis Adan.) infesta, Spreading 

 Hedge Parsley. 



