80 BRITISH ICHNEUMONS. [ Bassides 

are made use of here that have subsequently been more fully diagnosed 
and their species applied by later authors, of whom Thomson, in his 
masterly “ Ofversigt af arterna inom slagtet Zassus, Fab.” (O. E. xiv. 
1458), is certainly the foremost, though Vollenhoven, Bridgman, Brischke 
and others have assisted. Such of the palearctic species as I could find 
mentioned in my own library were tabulated and synonymised by me in 
1905, but a few others have since come to my knowledge, notably six 
species described by Szépligeti of Budapest in the fifth volume of Rovar- 
tani Lapok in 1898 and Homotropus sexcinclus by Brauns (Term. Fiiz. 1896, 
p- 273); but none of these are British and consequently hardly affect my 
paper ‘‘ On the Ichneumonidous Group 771phonides Schizodont’, Holmer.” 
(Trans. Ent. Soc. 1905, p. 419). Pfankuch has since revised Gravenhorst’s 
types. 
The economy of the Aassides is extremely interesting, but although 
many have been bred from Drp/era, apparently confining their attacks to 
the Syrphidae, which prey so exposedly and beneficially upon ApAzdrdae, 
very few details of their economy are at present available and it is to be 
desired that some close observer will ere long give us the result of his 
scrutiny in this direction.* Personally I believe them confined to 
Syrphidae. 
Table of Genera. 
(2). 1. Basalsegments deeplytransimpressed BaAssus, Aad, 
(1). 2. Basal segments not or hardly im- 
pressed. 
(10). 3. Metathoracic spiracles small and 
black. 
(7). 4. Face dull and distinctly punctate. 
(6). 5. Notauli wanting; scape not deeply 
excised aa Ai ae .. Homocinus, JZord. 
(5). 6. Notauli distinct; scape excised to 
centre ae ~ , .. ZOOTREPHUS, Zhoms. 
(4). 7. Face glabrous and strongly nitidulous. 
(9). 8. Areolet wanting; abdomen partly red PROMETHUS, 7homs. 
(8). g. Areolet present; abdomen entirely 
black Pe ve cod .. PHTHORIMUS, Forst. 
(3). 10. Metathoracic spiracles very large 
and pale’. os ee .. ITRICHOMASTIX, VodZ, 

BOLT 
ace mandible. 
* On August 8th, 1908, I found great masses of Aphis crataegi, Kalt., on asmall bush of Crataegus 
oxyacantha in my garden at Monks’ Soham House, Suffolk; they were by no means confined to the 
shoots, as suggested by Buckton, but were on both the underside of the much-curled but quite green 
leaves and upon the stems of last year’s growth; none were winged. They were so numerous as to 
attract numbers of insects to their abundant secretion; I noted, znter alia, the Diptera Homalomyia 
canicularis, L., Morellia hortorum, Fln., Calliphora erythrocephala, Mg., and C. vomitoria, L., Hyeto- 
desia ervatica, Fln., et spp., Lonchaea vaginalis, Fln. Sepsts punctum, F., Hydrotaea trritans, FIn., 
Tachista sp.,etc.; and many Lasius niger were sucking their cornicules. Three or four Bassus tri- 
cinctus, Grav., were flying round them doubtless in search of Syrphid larvae, of which I saw one. 
One Bassus, I noticed, brought her abdomen upin front of her face, intruded it to the base of a leat- 
stem, then straightened out her body and kept her terebra stationary (exactly as represented by 
Westwood, Introd. p. 140, fig. 76, 1), as though ovipositing, for half a minute; but I could find neither 
egg nor possible host in situ. The next morning I also saw among the Aphididae Ascia podagrica, 
Fab., Sepsis cynipsea, L., Phorbia spp., an ovipositing Syrphus balteatus (though I could find no eggs), 
Glypta flavolineata, Grav. and Trypoxylon attenuatum, Sm, Two of the female Aphids were now 
