54 BRITISH ICHNEUMONS. {Acanthocryptus. 



broad and coriaceous petiolar area, glabrous segments and white-banded, 

 incrassate antennae with Rhembobius to render either of Forster's genera 

 valid ; though the divergence of conformation of the areola, terebral val- 

 vulae, basal colour of the flagellum and their economy might enable us to 

 consider them distinct, were it not that in A. nigrita the pleural apophyses 

 and terebral valvulae are distinctly transitional. 



Tabic of Species. 



(6). I. Metathorax bituberculate ; areola not broader than long (Phvzelus, 



For St.). 

 (3). 2. Mesonotum black ; dentiparal areae 



transcostate i. NiGRiCOLLis, Thorns. 



(2). 3. Mesonotum red ; dentiparal areae 



simple. 

 (5). 4. Scutellar fovea transcostate ; hind femora 



dark 2. FLAGITATOR, Rossi. 



(4). 5. Scutellar fovea simple ; hind femora pale 3. HOPEI, J/i9r/. 

 (i). 6. Metathorax quadrituberculate ; areola 



strongly transverse (Rhembobius, 



For St.). 

 (8). 7. Abdomen and legs mainly red ; lower 



metathoracic spine strong 4. QUADRISPINOSUS, Grav. 



{j). 8. Abdomen and legs nearly entirely black ; 



lower metathoracic spine weak 5. nigrita, Grciz/. 



I. nigricollis, Thorns. 



Acanthocryptits nigricollis, Thorns. O. E. ix. 868, 9 ■ (?) Ichneiunon subtilicornis, 

 Gr. I. E. i. 529, excl. ? ; cf. Wesm. Mem. couron. Ac. Belg. 1859, p 72. 



9 . Head black, narrowed behind the prominent eyes ; frons deplanate, 

 smoothly and confluently punctate ; epistoma and clypeus convex, latter 

 truncately rounded and distinctly margined apically, and, with the centre 

 of the internal orbits, apex of cheeks and the mandibles, rufescent. 

 Antennae stout, filiform and apically obtuse ; scape and three basal 

 flagellar joints clear red, the next two sub-infuscate, central three or four 

 white and the remainder black. Thorax black, somewhat coarsely and 

 confluently punctate throughout ; areola pentagonal and not broader than 

 long, with costulae abbreviated and the dentiparal areae transcostate ; 

 basal area narrow and hardly explanate basally ; apophyses large, obtuse 

 and sub-reflexed ; petiolar area coriaceous, broad and strongly discreted. 

 Scutellum, and more rarely the post-scutellum, dull ferrugineous with its 

 basal fovea broad and simple. Abdomen glabrous and nitidulous through- 

 out, with the petiole black, the fifth and sixth segments sub-infuscate and 

 the anus dull stramineous ; basal segment bicarinate to beyond its centre, 

 and laterally margined throughout ; terebra rather longer than the basal 

 segment with the valvulae linear and not acuminate apically. Legs entirely 

 red, or with apices of the hind femora and tibiae sub-infuscate ; coxae 

 and trochanters a little paleY. Wings normal, slightly clouded ; areolet 

 somewhat large and parallel -sided, with the outer nervure not strong. 

 Length, 6 mm. 



$. Head black, with the mouth and face pale flavous. Antennae 

 shorter than the body, infuscate ; red, with the scape pale flavous beneath. 



