54 POMPILUS FUSCUS. 



cies in which they are present or absent. A close and constant 

 observation of these insects furnishes a clue to some apparent 

 difficulties. Amongst the British species, none are more emi- 

 nently fossorial than P. plumbeus and rufipes ; these species form 

 their burrows in hard sand-banks, the latter preferring those 

 situated on the sea-coast. P. variegatus prefers, on the contrary, 

 banks of soft sandy loam : I captured many specimens in the 

 act of burrowing in a situation of that kind in the north of 

 England. P. punctum is a species destitute of cilia on the ante- 

 rior tarsi, a sure indication of a difference of habit ; this species 

 constructs a number of mud-cells, placed irregularly side by side., 

 much resembling those constructed by Pelopceus : from a nest of 

 this description, discovered by the Rev. W. Delmar near Canter- 

 bury, five individuals were developed. These differences of habit 

 in species of the same genus have many parallels in other genera 

 of the Aculeata ; we may instance the genera Osmia and Mega- 

 chile amongst the Bees. 



Div. I. Anterior tarsi of the females ciliated j the intermediate 

 and posterior tibicewith a double row of spines. Pompilus. 

 Sp. 1-9. 



1. Pompilus fuscus. 



P. niger ; alis fuscis, apicibus nigris ; abdomine segmentis tribus 

 primis ferrugineis, cingulis nigris. Mas et Fam. 



Sphex fusca, Linn. Faun. Suec. 412. 1652 ; Syst. Nat. i. 944. 16 $ , 

 8f Cab. Mus. Linn. Soc. 



De Geer, Ins. ii. 822, t. 28. f. 6. 

 Sphex viatica, Scop. Ent. Cam. 294. 780. 



Fabr. Syst. Ent. 349. 20 ; Ent. Syst. ii. 210. 47 ? . 



Rossi, Faun. Etrus. ii. 62. 814. 



Mutter, Prodr. Zool. Dan. 160. 1864. 



Pompilus viaticus, Fabr. Ent. Syst. Suppl. 246. 4 ; Syst. Piez. 191. 

 12. 



Panz. Faun. Germ. 65. 16 ; Krit. Revis. ii. 118. 



Spin. Ins, Ligur. i. 68. 2. 



St. Faro, fy Serv. Encycl. Mc'th. x. 179. 1 ; Hym. iii. 431. 24. 



Van d. Lind. Hym. 342. 40 # ? . 



Shuck. Foss. Hym. 61. 12. 



Zett. Ins. Lapp. 437. 3. 



Dahlb. Mon. Pomp. 44 ; Exercit. Hym. 62. 4 ; Hym. Europ, 

 i. 57. 29. 



Brulle, Exped. Sc. de Moree, iii. 364. 804. 



Lucas, Explo. Sc. Alger. iii. 248. 



Wesm. Hym. Foss. Belg. 39. 15. 



