140 BRITISH ICHNEUMONS. 



an apical black line ; hind legs with the base of the stout femora and tarsi 

 fulvous, tibiae basally flavous. Length, 10-12 mm. 



Thomson, in 18S6, gave this species as a synonym of /. albiger, Wesm. 

 (1844), but it appears to differ in the shape of the areola and colour of the 

 tibiae. Berth, in 1894 queried its synonymy with /. niacrocerus, Thoms., 

 from which the filiform antennae and naVrower cheeks of the ? , the 

 fiavous scape beneath, immaculate front co.xae and black-lined inter- 

 mediate tibiae of the 6 , appear to distinguish it. 



Bridgman gives no localities, but says it appears to be uncommon in 

 Britain ; Bignell took it at Bickleigh, in Devon, on July 28th ; it is re- 

 corded from Essex ; and there are females in Marshall's collection, taken 

 at Plympton, in the middle of April, and at Darenth Wood. On the 

 Continent it is mixed with the preceding species. 



29. macrocerus, Thorns. 



Ichneumon macrocerits, Thoms. Ann. Soc. Fr. 1SS6, p. 20 ; Berth, lib. cit. 1S94 p. 

 639 ; Thoms. O. E. xviii. 1921, i 9. 



Head black ; $ with face and frontal orbits flavous throughout. An- 

 tennae slender ; ? distinctly sub-attenuate, white-banded ; $ fulvous or 

 piceous beneath, the joints internally carinate. Lines before and beneath 

 the radix of $ and the scutellum entirely flavous ; areola quadrate. Ab- 

 domen of $ with segments two and three, as well as basal angles of four, 

 flavous, three being quadrate. Legs black ; $ with tibiae tricoloured, 

 centrally stramineous, tarsi not or hardly dilated, scopulae entirely wanting; 

 (^ with anterior coxae often yellow-marked ; intermediate tibiae always 

 immaculate at apex. Length, 10- 14 mm. 



This species is so closely allied to /. confusorius as to need no detailed 

 description. The $ may be known therefrom by being a little larger ; by 

 the absence of the posterior coxal tuft ; the antennae more strongly 

 attenuate apically ; joints of flagellum longer beneath ; the second longer 

 than broad ; the cheeks rather longer ; fourth segment without pale apical 

 margin, third sometimes with a black basal fascia. From /. extensorius it 

 differs in the absence of the posterior coxal tuft ; the femora externally 

 punctate throughout ; the longer head ; antennae longer and much more 

 strongly attenuate apically, and in the posterior tibiae, which are stramine- 

 ous somewhat intermingled with red centrally, fuscous before the base 

 and rather broadly black at the apex. 



The c? also is very like that of / extensorius in having the posterior 

 tarsi black towards the apex, abdomen parallel-sided, the second and the 

 quadrate third segments are stramineous, the oblique thyridii and the gastro- 

 caeli are deeply excavated, and the areola sub-quadrate : but it differs in 

 the head being more strongly punctate and narrowed behind the eyes ; 

 clypeus apically truncate ; face, frontal orbits, and more convex scutellum, 

 flavous ; the flagellum ochraceous beneath ; anterior coxae with a pale 

 apical spot ; intermediate tibiae never black-marked on the inner side of 

 the apex. From /. confusorius it differs only in the pulvinate scutellum, 

 strong costulae and larger size. 



Bridgman records one male, identified by Thomson, from Brundall, in 

 Norfolk, in August, 1880 j it has probably been overlooked in Britain. 



