402 RHYNCHOPiiORA. [Scolytidce. 



clump anrl the larvae feed in an irregularly advancing column without 

 forming distinct galleries. . The dead body of the mother is usually to 

 be found at the end of her gallery, and it may thus often serve as a clue 

 to a species which is met with in the larval state. 



" The larval galleries usually commence at right angles to the mother 

 galleries at least at their middle ; but they often change their direction 

 irregularly the different shapes being characteristic of the species. 



" Their length is variable and depends on the extent to which they 

 are channelled on the wood. In some species the galleries, which 

 score the wood deeply, are only about one inch in length, while in 

 others they are often between four and five inches long and sometimes 

 very irregular ; they end in an oval pupal chamber from which the 

 imago escapes by gnawing a flight-hole. Besides these holes others are 

 made at intervals along the ' mother galleries ' for ventilation. 



" In the wood-borers the females alone make the entrance-holes, which 

 lead sometimes to tangential galleries from which the larval workings 

 start, as in Trypodendron ; or they form a series of repeatedly bifurcat- 

 ing passages, as in Xyleborus, in which larvae, pupae and immature beetles 

 occur together. In the second case there are no larval galleries and the 

 larvae appear to feed on sappy exudations or on the mycelium of a fungus 

 growing on the walls. 



"In the wood-boring forms pupal chambers and flight-holes are not 

 found, the imagos emerging by the entrance-tunnel. In certain genera, 

 as Xyleborus, the males are apterous, and do not quit the tree in which 

 they are bred ; here they fertilize the females immediately after meta- 

 morphosis." 



The family as catalogued by Gemminger and Von Harold (Munich, 

 1872), comprises seventy genera and seven hundred and fifty species, 

 which are very widely distributed ; in the European catalogue of Heyden, 

 Reitter and Weise thirty-two genera and about one hundred and thirty 

 species are enumerated, and other genera have since been created; the 

 number of British species is about fifty : M. Bedel (in the Faune des 

 Colcopteres du bassin de la Seine, p. 3) separates the Platypodidse from 

 the Scolytidae as separate families on the shape of the metatarsus : in 

 sketching out the arrangement of the family for this work I had, how- 

 ever, come to the conclusion that there was not sufficient difference to 

 warrant this separation, and was afterwards pleased to find that on page 

 305 of his work (foot-note 1) M. Bedel has again united them as sub- 

 families of one family Scolytidie ; the family will therefore be thus 

 divided : 



I. First joint of tarsi (or metatarsus) much shorter than the re- 



maining joints united ; sides of i horax not emarginate for the 

 reception of the legs; eyes oblong or divided ; head never 

 . broader than thorax SCOLTTIN.E. 



II. First joint of tarsi (or metatarsus) almost as long as the 

 remaining joints united ; bides of thorax cmarg'iDate for the 



