Piti/ogeriej.'] EnrxcnopHonA. 443 



male with the terminal excavation of the elytra 

 terminated behind with small setigerous ercnu- 



Litions P. BiDEXrATCS, Herlst, 



ii. Body behind thorax two and a half times as long 

 as broad ; male with the terminal excavation of 

 the elytra without setigerous crennlations . . P. QUADRIDENS, Hart. 



The following character is given for Section II. by some authors : 

 " Male with the internal margin of each elytron armed behind with a 

 very small tooth, followed by a large somewhat curved spine " ; in 

 P. bidentatus, however, this tooth does not occur in the type form, but 

 only in certain specimens which must be referred to the var. B. of 

 Eichhoffs monograph ; the same applies to P. quadridens ; the small 

 third tooth is not found in the type ; there is a larger form Avith the 

 three teeth on each elytron (P. bigtridentahu, Eich.) which has been 

 thought to be a distinct species ; the females of P. bidentatus and P. 

 quadridens have small tubercles bearing hairs instead of the large teeth 

 in the males, and in the latter species the female often has a thick 

 greyish mass of hairs clothing the forehead ; it is, however, doubtful 

 whether the two species are really distinct. 



A confusion regarding the sexes has sometimes arisen ; Eichhoff in 

 his monograph " Ratio Tomicinorum, 1878," follows Thomson and 

 Chapuis and calls the toothed forms the female ; in his " Europaischen 

 Borkenkilfer, 1881," he corrects this, and says he does so after micro- 

 scopical examination of the generative organs, and also because the 

 details of their life history require it as formerly shown by Eatzeburg; 

 this appears to settle the question. 



P. chalcogrraphus, L. Eeddish-brown, with the thorax and base 

 of elytra pitchy, or entirely reddish-brown, shining, with scanty 

 pubescence ; antennae and legs testaceous ; thorax longer than broad, 

 scabrous in front, finely and rather closely punctured behind, with a 

 central line and the side portions of the punctured space smooth ; elytra 

 with very fine punctured stria? which are almost obsolete on disc, and 

 wanting at sides towards apex, apical impression near suture deep and 

 broad and furnished on each side with three tubercles, of which the first 

 is situated a little behind the middle. L. H-2 mm. 



Under bark of firs and pines ; not common; Mickleham (Power) ; London district, 

 old pines (Stephens) j Scarborough ; Northumberland and Durham district, " Sunder - 

 land/' Rev. E. Kirwood ; Scotland, very local, Clyde district (Glasgow). 



P. bidentatus, Herbst. (biclens, ~F.). Pitchy-black, rather shining, 

 clothed with fine and scanty pale pubescence ; antenna? ferruginous ; 

 legs fusco-testaceous ; thorax longer than broad, scabrous in frout, 

 rather strongly punctured behind, with a narrow elevated central line 

 and a round space at sides smooth ; elytra with punctured striae at 

 sides and rows of rather large punctures on disc, interstices with rows of 

 smaller punctures. L. 2-2f mm. 



