THE ENTOMOLOGIST. 323 



form, observable in these species, must, in ray opinion, prove 

 conclusive of their being perfectly distinct species, as distinct 

 from each other as any two or more of the genus Borabus : 

 this I am prepared to establish by the same tests that 

 I applied in separating the males of that genus, namely, by 

 an examination of the sexual organs : taking this test, in 

 conjunction with those of sculpture and form, I have no 

 hesitation in affirming that the difference between S. gibbus 

 and S. rufescens is quite as great as that which can be found 

 among the six British species of the genus Vespa. 



Dr. Sichel examined 3200 specimens of the four species of 

 Sphecodes, and he stales that he found it impossible to sepa- 

 rate them into species : they merged so insensibly one into 

 the other that he could arrive at no other conclasion than 

 that they were varieties and sub-varielies of one and the 

 same insect. 



Tn addition to this laborious investigation, he adds that, 

 after examining the sexual organs of the males, " as well as 

 he could see," they were absolutely the same. Another 

 circumstance is recorded in confirmation of the opinion he 

 arrived at, namely, that he captured all the varieties within 

 the space of about two feet (" thirty centimetres.") 



Dr. Sichel has obligingly sent, together with a copy of his 

 paper, a series of specimens, intended to show the gradual 

 merging of one species into the other. I must confess my 

 inability to detect any connecting-links between the s])ecies. 

 I shall therefore endeavour to point out those constant 

 distinctive specific characters which separate the species. 

 ] may also remark that Sphecodes subquadratus is rare in 

 this country : after my first capture of the species, nearly 

 twenty years intervened before I again found it ; and it must 

 be understood that during that interval I assiduously col- 

 lected bees on each return of summer, capturing numbers of 

 Sphecodes, but not finding a single specimen of S. sub- 

 quadratus. 



S. fuscipcnnis is allowed on all hands to be a good species : 

 it must be extremely local, as no Entomologist has taken ifc 

 for many years; it is probably confined to the county of 

 Devonshire, where the i'ew specimens found in cabinets of 

 Brilisli bees are said to have been captured. 



In studying the genus Sphecodes the first diflTiculty that 



