Pezomachm?^ BRITISH ICHNEUMONS. 1 79 



one of the most constant and most obvious features of these insects ; the 

 basal segment was found to vary considerably in shape in individuals of 

 the same species, and the scutellum to depend too much on individual 

 development to be reliable. The acetabulae, the hollows in which the 

 coxae revolve, have been denoted by Thomson, together with the inflection 

 or continuity of the genal costa ; but these features are rarely to be 

 examined in our carded specimens, and have been but little employed in 

 the following tables, which it is hoped will serve to elucidate this difficult 

 genus till better can be compiled. 



Sub-genera might, with propriety, be erected, based on the very distinct 

 shapes exhibited by the basal flagellar joints, sometimes moniliform, some- 

 times strongly elongate with and without their apices nodulose. This is 

 impossible in the present work, as no reference to their shape is made by 

 the older authors. 



In Beaumont's collection (now in mus. Chitty) I have seen British 

 specimens purporting to represent P. vorax, Forst., from Harting in 

 Sussex, and F. proditor, with P. ambulans, Forst., from Appledore in Kent; 

 these I was not then in a position to confirm and — since their captor often 

 declared he " never opened a book ! " — I have here ignored. Richardson 

 has bred unspecified Pezomachi from CoIeopJwra flaviginella and Nepticula 

 centifoliella at Weyaiouth ; and others are mentioned at Ent. Annual, 

 i860, p. 44, and 1861, pp. 40-41, and E.M.M. 1872, pp. 162 and 180 ; 

 cf. also Brischke's Kiirzere Mittheilungen liber die Gattung Pezomachus 

 (Schr. Nat. Ges. Danz. 1877-78), and my paper on the genus (Trans. 

 Leicester Phil. Soc. 1899, pp. 295-301). To illustrate how little reliance 

 should be placed upon Forster's " species," it is only necessary to add that 

 he described a hundred and two of them from a single specimen only. 



Schmiedeknecht in 1906 adds nothing whatever to our knowledge of 

 the genus nor its classification. 



Table of the Females. 



(14). I. Basal flagellar joint shorter than the second. 

 (13). 2. Fifth flagellar joint not shorter 



than broad. 

 (10). 3. Fifth flagellar joint quadrate. 

 (9). 4. Abdomen not closely nor uniformly 



punctate. 

 (8). 5. Clypeus apically immarginate ; in- 

 terstices glabrous. 

 (7). 6. Apophyses wanting ; central seg- 

 ments elongate i. SVLVICOLA, Forst. 



(6). 7. Apophyses distinct ; central seg- 

 ments transverse 2. AQUISGRANENSIS, /^£>>x/. 



(5). 8. Clypeus apically margined ; inter- 

 stices alutaceous 3. KlESENWETTERl, Forst. 



(4). 9. Abdomen closely and uniformly 



punctate 4. ZONATUS, /s»j-/. 



(3). 10. P'iflh flagellar joint longer than 



broad. 

 (12). II. Abdomen distinctly punctate ; cen- 

 tral segments callose 5. VULPINUS, Gra7>. 



(if). 12. Abdomen obsolclely punctate ; cen- 

 tral segments normal 6. COSTATUS, /►V/V/i,'-. 



N 2 



