440 BHTNCHOPHOKA. 



usual "typograph" in the bark, there is formed a stellate system radi- 

 ating from a breeding-chamber (Rammel-kammer). 



The most efficacious way of proceeding against the ravages of Tomicus 

 typography,* is by the establishment of " fangbaumen ; " that is, by ring- 

 ing the trunks of a number of trees selected at intervals in the forest, 

 shortly before the flight-time of the insects ; these trees will be selected 

 as breeding-places and may then be cut down, and the bark with the 

 contained broods destroyed. There may be as many as three generations 

 of Tcmicus typographus in the year, with favourable weather ; it is 

 therefore imperative to see that the trees thus prepared are punctually 

 destroyed before the insects have time to develop. 



Of the fourteen or fifteen European species five are found in Britain; 

 these. may be distinguished as follows: 



I. Posterior excavation of elytra not abrupt, usually 

 very oblique, and occupying from a third to a half 



of the suture. 

 i. Posterior excavation of elytra with six teeth on 



each side, the three upper ones being small and 



the fourth the largest; length 5i-8 mm T. SEXDENTATUS, Burn. 



(stenographus, Duft.). 

 II. Posterior excavation of elytra with four teeth 



on each side, the uppermost one being often in- 

 distinct, and the third the largest j length 4 J-5J 



mm T. TYPOGBAPHUS, L. 



iii. Posterior excavation of elytra intermediate in 



abruptness between the two preceding and the two 



following species, with three teeth on each side, 



the lowest one being the largest T. ACTTMINATTTS, Gyll. 



IT. Posterior excavation of elytra abrupt occupying only 



the apex of the elytra, 

 i. Elytra with more strongly punctured stria; and 



with the posterior excavation larger and more 



strongly toothed at the sides ; club of antennae 



rounded at apex, with the sutures between its joints 



straight T. IARICIS, F. 



ii. Elytra with less strongly punctured striae and 



with the posterior excavation smaller and less 



strongly toothed at the sides ; club of antennae 



subtruncate at apex, with the sutures between its 



joints curved T. NIGRITUS, Gyll. 



T. sexdentatus, Born. (stenograpJius, Duft.; typograplius, Steph. 

 nee L.). A large and conspicuous species ; pitchy black with the 

 elytra reddish brown, but variable in colour, somewhat immature speci- 

 mens being lighter and often entirely testaceous, shining, clothed with 

 very long yellowish grey villose pubescence, which is thicker at sides 

 and extremities ; antennae and legs ferruginous ; thorax large, longer 

 than broad, scabrous in front, diffusely and finely punctured behind ; 

 elytra only a little longer than thorax, with deep punctured stria?, inter- 

 stices smooth on disc, rugose at sides and apex, apex excavated, the 

 excavation being oblique and occupying from a third to a half of the 



