Exyston | BRITISH ICHNEUMONS. 191 

EXYSTON, Schiédte. 
Schiéd. Guér. Mag. Zool. 1839, Ins. p. 12, nota. 
Head subbuccate and elongately pubescent; clypeus arcuately dis- 
creted and a little elevated ; mandibular teeth acute and of equal length. 
Thorax distinctly pubescent with the epicnemia elevated behind the front 
coxae. Abdomen clavate; first segment narrow and basally strongly 
dilated, with its spiracles central. Legs slender with the tarsal claws 
simple and the intermediate tibiae unicalcarate. 
The species of this genus, which occur in grassy and especially dry, 
sunny places, are at once recognized by the strongly pubescent head and 
thorax, clavate abdomen, strongly dilated first segment and the un- 
pectinate claws. About a score have been described, for the most part 
from North America, though Thomson has separated several from the 
type of the genus, which alone has hitherto been supposed to occur in 
Britain. Two are of doubtful occurrence.* 
Table of Species. 
(2). 1. Basal segment elongate, postpetiole 
twice longer than broad .. .. I. CINCTULUM, Grav. 
(1). 2. Basal segment short, postpetiole not 
twice longer than broad. 
(4). 3. Face white-marked; abdomen mainly 
rear te ne e .. 2, BREVIPETIOLATUM, Zh. 
(3). 4. Face entirely black; abdomen not 
red-marked wa = .. 3. SUBNITIDUM, Grav. 
1. cinctulum, Grav. 
Ichneumon cinctulus, Gr. Mem. Ac. Sc. Torin. 1820, p. 359, ¢. Mesoleptus 
cinctulus, Gr. I. E. ii. 37; Ste. Ill. M. vii. 218, ¢. Exyston cinctulus, Holmgr. Sv. 
Ak. Handl. 1854, p.73, ¢; lib. cit. 1855, p. 246; Voll. Schets. I, pl. iii, fig. 21; 
‘homs, ©. B. ix.S882-g ¢- 
Head subbuccate and scarcely constricted posteriorly; clypeus dis- 
creted. Antennae somewhat shorter than body. Metathorax rugose 
with five areae ; pleurae diffusely punctate; scutellum elevated and api- 

* EXYSTON ALBOCINCTUS, Grav. 
Ichneumon albicinctus, Gr. Mem. Ac. Sc. Torin. 1820, p.375, ¢._ Tryphon albocinctus, Gr. I. E. ii. 
204; Ste. Ill. M. vii.245; Fonsc. Ann. Soc. Fr. 1849, p. 223, ¢. Exyston albocinctus, Pfank. Zeits. 
Hym. Dip. 1906, p. 222. 
An elongately white-pubescent species. Face black with the palpi, centre of mandibles and apex 
ofclypeus flavous; antennae as long as body, piceous with the under side ferrugineous; metathor- 
acic areae indistinct, with areola broad and transversely rugose ; spiracles oval. Scutellum apically 
red. Abdomen red with its base black, and margins of the segments whitish ; first segment deeply 
foveate and auriculate basally; anterior legs flavous; hind ones black with tibiae centrally and 
femora apically flavous; anterior femora laterally infuscate; areolet irregularly subpetiolate. 
Length, 9 mm. 
Larger and stouter than E. cinctulum, with thorax somewhat more coarsely punctate. 
Gravenhorst had but two Italian males and de Fonscolombe records it from Aix. Stephens claims 
to have taken the species rarely at Darenth Wood in July; but his specimens, now in the British 
Museum, are referable to E. brevipetiolatum. 
EXYSTON TRICOLOR, Grav. 
Tryphon tricolor, Gr. I. E. ii.207; Ste. Ill. M. vii. 246, ¢. Exyston tricolor, Pfank. Zeits. Hym. 
Dip. 1906, p. 223. 
This species is very closely allied to E. cinctulum in its elongate basal segment, etc., but may at 
once be known by its great Size of 11mm. No one recognised it from 1829 to 1906, when Pfankuch 
found the single male type from Frankfort to belong to the present genus, except Stephens, who pro- 
fesses to have found it toth at Darenth Wood and the New Forest rarely in June. A great deal more 
evidence is requisite to include either this or the above species in our Fauna, 
