92 ICHNEDMONID.1-. 



This very distinct genus may be knov\'n by tlie transversely 

 rugose thorax, somewhat relating it to the XoKiDinES, between 

 which and Coleocentriis it would appear, as is pointed out by 

 Thomson (Opusc. Ent. p. 737), to form a transitional group oi:' 

 species. Its European representatives are very well known to 

 prey upon the large wood wasps, of the family Siricib.e, and 

 doubtless their Indian relations follow a similar means of livelihood; 

 in fact, Mr. E. P. Stebbing tells us (Journ. Bombay Nat. Hist. 

 Soc. xvi, p. 684) that both Thalessa and Bhi/ssa attack wood- 

 feeding grubs in India, though I have seen and heard of no 

 representatives of the former genus thence. He does not, 

 however, state that these grubs are the larvae of Sirex, but I have 

 seen females of the latter, differing from the Palaearctic S{re.v 

 gigas, L., only in having the prothorax ferruginous and the hind 

 tibia) partly black, in the collection of Mr. Ernest Elliott, from 

 Haidarabad, in Berar; and three kinds of Xiphydria have already 

 been found in India {cf. Spolia Zeylanica, 1905, p. 71). The 

 Linnean Sirex has been noticed by Eadoszkovsky (Horee Ent. viii, 

 p. 200) as far east as the Caspian Sea ; and the genus is known 

 to be very widely distributed. 



49. Ehyssa persuasoria, L. 



Ichneimiofi persuasorius, Linufeus, Faun. Suec. p. 400 ; Donovan, 



Brit. lus. XV, p. 622 ($). 

 Pimj^la 2^ersiutsoria, Fahricius, Syst. Piez. 1804, p. 112. 

 Rhyssa jJersimsoiia, Gravenhorst, Ichn. Eur. iii, 1829, p. 267 ; 



Holmgren, Sv. Ak. Ilandl. 1860, no. 10, p. 9; Taschenberg, Zeit. 



Ges. Nat. 1863, p. 251 ; Yollenhoveu, Pinac. pi. xi, tigs. 5, G 



(c??)- 

 Head laterally intumescent and as broad as the eyes, frons and 

 face subglabrous ; epistoma deplanate, clypeus narrow and 

 centrally obtusely produced; palpi and all the orbits more or less 

 white, though sometimes immaculate on the vertex ; c? with 

 the face also entirely white. Antenmc filiform, shorter than 

 body, scape black ; flagellum generally dull ferruginous beneath 

 or even entirely, with the joints elongate, apically nodulose 

 and the basal one distinctly curved. Thorax subcyliudrical, 

 black; metanotum centrally canahculate; propleural marks, 

 pronotum broadly in front, a line before and a callosity beneath 

 radix, a mark above the intermediate coxDe and another above the 

 hind ones, whicli latter sometimes coalesce across the apex of 

 tlie metathorax, white. Sculellum and postscutellum entirely or 

 apically white ; very rarely black. Abdomen quite twice as long 

 as head and thorax, cylindrical and about as broad as the latter, 

 in 5 laterally suhcompressed ; basal segment gradually constricted^ 

 of S thrice as long as broad, glabrous and centrally sulcate ; one 

 or two basal segments apically, and laterally towards the apex, 

 white ; second or third to seventh with lateral and infra-apical 

 spots on either side more or less broadly white; terebra nearly a 



