l68 BRITISH ICHNEUMONS. 



generally basally incrassate, of (? sub-serrate or with the joints not elon- 

 gate-cylindrical. Thorax not convex ; pronotum not pale, pro-pleurae 

 inferiorly striolate ; metathorax sub-mutic, costulae generally wanting ; 

 mesosternal epicnemia interrupted above. Scutellum not gibbose. Ab- 

 domen with gastrocaeli and thyridii hirge and deeply impressed, as broad 

 as the strongly sculptured, usually convex, but never simply punctate, 

 intervening space ; seventh segment not white ; fourth ventral not plicate ; 

 ^ valvulae apically broadly rounded ; terebra of ? almost entirely con- 

 cealed. Wings with costa and tegulae usually nigrescent. 



The features of this genus, as indicated by its author, are six in number, 

 viz. : The serrate antennae of the ($ , the strongly developed gastrocaeli, 

 invariably immaculate anus, not plicate fourth ventral segment, the elon- 

 gate valvulae which are longer than the hypopygium and the membraneous 

 apex. Thomson (/oc. cit.) points out that some of the species of this 

 genus, e.g. C. sputator and C. ho/iiocerus, might be transposed to Stenich- 

 neumo7i. 



Wesmael, in 1844, drew the genus Ambly teles from Ichneumon, Grav., 

 and divided it ("Amblypygi Europaei," 1854) into two main groups; 

 those species with the gastrocaeli small and the intervening space flat, 

 he called Microsticii ; those with the gastrocaeli large and deeply im- 

 pressed with the interval convex and longitudinally sculptured, constituted 

 his Macrostidi. The former he sub-divided into four colour-groups and 

 the latter into three, of which the Crioceri differed from the Leptoceri in 

 having the basal flagellar joints sub-moniliform and the Coryphaei from 

 both in their narrow, elongate areola, etc. Thomson ("Notes Hymen.") 

 held the presence or absence of a fold on the fourth ventral segment to be 

 of primary importance and the size of the gastrocaeli as secondary to it ; 

 but in " Opusc. Ent." he raises the Macrostidi to the genus Ctenic/meunion, 

 and divides the Microstidi into two others based upon the ventral folds, 

 development of the epicnemia and the position of the hypopygium in 

 relation to the terebra, relegating the Coryphaei in part to his genus Fro- 

 tidineiimon and erecting a new one, Trichoiabus, for the reception of 

 A'/ib/y teles strigatorii{s, Simong the F/atytirifii. Ashmead has again divided 

 the latter's genus Aniblyteles into two, in one of which the metathoracic 

 apophyses are distinct and in the other but tuberculiform ; but unfor- 

 tunately he gives A. palliatorius, which has distinct though small spines, 

 as the type of his mutic genus, Psetidamhlyteles. The value of the man- 

 dibular dentation, so difficult to follow in the Diadromus group, is here 

 discounted by such species as A. eqtntatorius and A. castanopygiis, in 

 which the lower tooth, though almost wanting, is discernible ; and it is 

 certainly difficult to seize good characters by which to distinguish these 

 insects in both sexes. 



The genus Aniblyteles of Wesmael was at best artificial and divided from 

 his genus Ichneumon at first solely by the fact that the hypopygium of the 

 females covered the base of the terebra and that the female anus was 

 obtuse. To this Holmgren ("Ichn. Suecica," 1864) added that the males, 

 after death, possessed through the fermentation of the bile a longitudinal 

 fold on at most the second and third ventral segments, whereas in Ich- 

 neumon the fourth was also plicate, but this is incorrect, for about a third 

 of the species of Aniblyteles (sensu Wesm.) have the fourth segment folded 

 in the males. They are consequently extremely difficult to distinguish 

 therefrom. Nevertheless the males have the head less narrowed behind 



