Otoblastus ] BRITISH ICHNEUMONS. 189 

OTOBLASTUS, Forster. 
Foérst. Verh. pr. Rhein]. 1868, p. 201 ; Thoms. O. E. ix. 895. 
Clypeus slightly excavate discally; eyes not internally emarginate. 
Metathoracic areae complete. Abdomen sessile and apically clavate ; 
first segment acutely dentate on either side at its base, and discally bi- 
carinate. Legs stout; tibial calcaria distinct; tarsal claws mutic. 
Areolet oblique, subsessile ; stigma broad; nervellus opposite and inter- 
cepted hardly below its centre. 
Unique in its basally auriculate petiole; it has the facies of Crenzscus, 
in which genus it has hitherto stood in our Catalogue, though Marshall 
has marked our single species (in MS.) ‘‘ Not Cileniscus but Tryphon.” 
We possess the only palaearctic species, though several others are 
described under this genus by Davis from America. 
1. luteomarginatus, Grav. 
Tryphon luteomarginatus, Gr. I. E. ii. 146, 9. Otoblastus luteomarginatus, 
Mhoms: Oo E. 1x. 900). 9": 
A small and stout black species with the mouth, clypeus, face, frontal 
orbits and underside of the filiform antennae, flavous. ‘Thorax stout, 
short and strongly convex, with the scutellum large and the fully areated 

metathorax abruptly declived apically. Abdomen stout and apically sub- 
truncate, black with apices of all the basally constricted segments narrowly 
flavidous; basal segment margined, evenly punctate and laterally sub- 
parallel; terebra slightly exserted, ¢ valvulae large. Legs short and 
stout, stramineons with the anterior basally testaceous; hind coxae, 
trochanters, femora and apices of the whitish tibiae, deep black. Length, 
5—6 mm. 69. 
