170 THE ENTOMOLOGIST. 



A MONOGRAPH of the Genus ACRORICNUS, Ratzeburg. 

 Family Ichneumonid^ : Subfamily CRYPTiNiE : Tribe Cryptides. 



By Claude Morley, F.Z.S. 



This genus has been thrice described under distinct names : 

 first as above by Ratzeburg (Ichn. d. Forst. iii. 1852, p. 92), 

 secondly as Xenodocon by Forster (Verb. pr. Rbeinl. 1855, 

 p. 237), and Kriechbaumer (Ent. Nachr. 1878, p. 22 ; cf. also 

 p. 251 et lib. cit. 1879, p. 3), and finally as Linoceras by Dr. 

 Taschenberg (Zeits. Ges. Naturw. xxv. 1865, p. 105); though 

 its distinction from the earlier Osprhynchotus — of which I treated 

 in Entom. 1914, p. 23 — was only so recently understood that 

 Dalla Torre commingled the species of both in 1900. From the 

 latter it is at once recognised by the possession of two instead 

 of a single basal, metathoracic transcarinae; and from both that 

 genus and the closely allied Joppidmm, Walsh, in its hyaline or 

 subhyaline wings, which in both those genera are nearly or 

 quite nigrescent or infumate throughout. Only six species are 

 represented in the British Museum and my own collection ; a 

 profusely ornate form from Persia (var. pidcher) is described by 

 N. Kokujew in his " Hymenoptera asiatica nova" (' Revue Russe 

 d'Entomologie,' 1905, p. 208) of A. elegans, Mocs. (Magy. Akad. 

 Termesz. Ertek. xiii. 1883, p. 11, female), which I do not know. 



The genus is of peculiar interest on account of its parasitism 

 upon bees and wasps, members of its own Order. 



Table of Species. 

 (10). 1. Upper and lower margins of the discoidal cell parallel. 

 (7). 2. Posterior metanotal transcarina entire throughout. 

 (6). 3. Mesonotum and most of the abdomen black. 

 (5). 4. Face, abdomen and scutellum black ; legs 



rufescent 1. macrobatus, Grav. 



(4). 5. Face, abdominal bands and scutellum pale ; 



legs flavescent 2. seductor. Scop. 



(3). 6. Mesonotum and abdomen brick-red, with 



flavous markings . . . .3. sTjriacus, Mocs. 

 (2). 7. Posterior metanotal transcarina centrally 



obsolete 



8. Metathorax long, subdeplanate ; face flavous 



4. ])eronakLs, Cam. 



9. Metathorax short, convex ; face centrallly 



black 5. ambulator, Smith. 



(1). 10. Upper and lower margin of discoidal cell dis- 

 tinctly divergent apically. 



(12). 11. Nervellus centrally intercepted ; abdomen red- 

 marked . . . . .6. melanohucus, Grav. 



(11). 12. Nervellus intercepted above centre; abdomen 



all black 7. junceus, Cress. 



