to the History of Stylops. 129 



I have seen in other cabinets, are invariably attacked. I therefore 

 imagine the discovery of a colony of that species of Andrena is 

 all that is requisite to supply Stylnps in abundance. 



The following is a list of British Andrenidce, which I have ob- 

 served to be subject to the parasitic attacks of Stylops : — 

 Halictus minutus, $ .' 



nitidiusculus , $ . 



longidus, 2 . 



Andrena bicolo)\ ^ , $ . 



Trimrnerana. $,2- 



nil'ida. ^ , $ . 



varians. $. 



xanthura, $ . 



Afzeliella. $ . 



fuscata. 2 . 



' chrysosceles, 2 • 



convexiuscula. ^ , 2 • 



It will be seen by this list that none of the species which are 

 very pubescent, or have the segments thickly fringed with pu- 

 bescence, have been observed to be infested, although such would 

 appear to be the species most likely to collect the larvae when 

 visiting those flowers which contain them. 



The only specimens of ^nc?;eMi£?<:e which I have seen infested, not 

 British or Continental, are a male and female Andrena from East 

 Florida, closely allied to the European A. chrysosceles ; the head 

 and thorax of two female Stylops protrude from beneath the fourth 

 segment of the abdomen of the female, and one from beneath the 

 fifth segment of the other sex, a male Stylops having emerged from 

 beneath the second segment. I have also seen a single specimen 

 of an Andrena from East Florida infested by a single female 

 Stylops, and three specimens oi^ Andrena victima from Nova Scotia. 

 Specimens of l^olistes Gollica, infested by Xenas vesparum, are to 

 be seen in most collections of Hymenoptera, and possess an addi- 

 tional interest, from the fact of the celebrated Rossi having first 

 discovered these remarkable insects infesting that genus of wasps. 



Fam. SPHEGIDiE. 



Species of the genus Ammophila appear to be particularly sub- 

 ject to the attacks of Stylopidce. I have observed the following : — 



Ammophila holosericea, ? , from Sicily. A male parasite having 



VOL. v. N.S. PART III. — SEPT. 1859. K 



