A MONOGRAPH OF THE GENUS ACROEICNUS. 171 



[Of the remaining five species included in this genus, the 

 three described from Brazil by Taschenberg (Zeits. Ges. Nat. 

 1876, pp. 71-74) have not been mentioned since first brought 

 forward ; nor has A. edwardsi, Cress. (Proc. Acad. Philadelphia, 

 1878, p. 365) ; though the last, A. doutieri, Provancher (Natural. 

 Canad. 1874, p. 150), has twice been figured {lib. cit. 1879, 

 p. 110, fig. 2b et Eaun. Ent. Canad. Hym. 1883, p. 343, 

 fig. 35ab).] 



1. AcRORiCNus MACROBATus, Grav. 

 Crt/ptus macrohatas, Gr. Ichn. Europ. 1829, ii. p. 440; Acroricnus 

 schaumii, Ratz. 1852, p. 92. 



The only species with entirely black abdomen and meta- 

 thorax. Folard sent a pair to the Eev. T. A. Marshall from 

 Avignon in August and September, 1891-2 ; of two in Euthe's 

 German collection, one was captured by Bermuth, possibly with 

 Eatzeburg's type ; Dr. L. W. Sambon found a female in Ostia 

 during 1901 ; and Bucheker had the species from Lagern on 

 August 8th in " Alp. That." in the Bngadine above St. Moritz, 

 from Zurich on July 1st, and elsewhere in Switzerland. This is 

 the only British species of the genus, and has hitherto been 

 known only from the extreme south— Hampshire, Isle of Wight, 

 and Devonshire — though there appears to be no reason for 

 supposing it confined to those counties, since Dr. A. Eoman tells 

 me that in Sweden it extends "at least as far north as western 

 Dalecarlia " (latitude 61° — that of the Shetland Islands) — and 

 that it is there not rare in dry localities. Its known British 

 range is, however, extending, for I have recently seen specimens 

 from Eomsey in Hants (Buckell), Milford Haven in Wales on 

 June 4th, 1910, and Stradbally, co. Waterford, in Ireland, at the 

 end of June, 1907 (Andrews). It is known to parasitise several 

 species of the wasp genus Eumenes and the bee genus Osmia. 



2. Acroricnus seductor, Scop. 

 Ichneumon seductor, Scop. Delic. Faun. 1786, p. 57 ; Xenodocon 

 rnficornis, Forst. 1855. 

 A large and handsome black and flavous species ; occurring 

 on both north and south shores of the Mediterranean from 

 Provence to Algeria, but probably commonest in Italy. The 

 Eev. T. A. Marshall told me in 1898 that he was then noticing 

 the species abundantly about the nests of a wasp in stone walls 

 at Ajaccio in Corsica, but his collection contains but a single 

 example sent by Folard, who took it at Avignon on October 1st, 

 1892 ; I possess the species from Oldenberg's collection, taken 

 in the middle of July, 1899 ; and the British Museum has a 

 short series, taken in Italy by Birch, as well as in Albania 

 between 1843 and 1850 by Sir Sydney Saunders, who says of 

 one particular male there " Parasite on Pelopmis spirifex," 



