20 Eev. T. A. Marshall's monograph of 



the abdomen in length. Length, $ 1^ ; wings, 3 : J 1^ — 2^ ; 

 wings, o — 4^ lin. 



Var. 1, ?. Metathorax almost smooth; middle and hind coxae 

 black or testaceous. Rare. 



Var. 2, 5 . Head rufo-testaceous, stemmaticum black. 



Var. 3, 5 . Orbits of the eyes entirely black. 



Var. 4, g- . Head black, only the mouth and apex of the genae 

 rufo-testaceous. 



Var. 5, J . Second segment of the abdomen with two additional 

 black spots, covering the thyridia. 



Antennae ? 29 — 37-jointed, as long as the body, sometimes 

 ferruginous beneath towards the aj)ex. Colours variable : some- 

 times the prothorax is testaceous ; the mesothorax may be bor- 

 dered with the same coloiir, its disk longitudinally marked with 

 two lines, or its sides may be testaceous. On each side of the base 

 of the rugulose metathorax is a small smooth space : the longi- 

 tudinal carina is sometimes indistinct. Abdomen elongate-oval, 

 not very shining ; segments 1 — 2 covered with rugulosities crossing 

 each other irregularly ; the following segments transversely acicu- 

 lated. Segment 1 black, 2 rufo-testaceous with a medial black 

 spot, quadrate, or rounded behind. The 3 next segments have 

 usually larger rectangular black patches, forming a continuous 

 band as far as the 5th inclusive : these vary considerably, and are 

 liable to be diminished to mere disconnected streaks. Legs rufo- 

 testaceous, the last joint of the tarsi blackish ; hind coxae some- 

 times black at the base. Wings hyaline, or very slightly tinted ; 

 stigma and nerves blackish ; but the stigma is sometimes pale in 

 the 5 (according to Wesmael, and in one British specimen). 



The g is similar, but smaller ; antennae 84 — 40-jointed, longer 

 than the body. The black abdominal stripe is usually dilated 

 posteriorly, covering the entire apical half of the abdomen, except 

 a narrow margin all round. Not to be confounded with the g of 

 mediator, Nees, sp. 16, which has the abdomen smooth after the 3d 

 segment, segments 2 — 3 entirely testaceous, &c. 



The ? is most likely to be confused with lojigicollis, 

 Wesm., sp. 6. 



The length of the terebra given by Nees is two-fifths 

 of the abdomen, which corresponds with most of the 

 British specimens, although in some it is rather longer. 

 Wesmael, in his diagnosis, states it to be as long as the 

 abdomen, but subsequently admits that it is sometimes 

 shorter. It is variable, within certain limits, but does 

 not in this country attain the length exhibited by the 

 Belgian specimens. 



