Latreille first termed the group to which Bitoma belongs 

 Xylophagi, but he has since divided it, and called the portion 

 that includes our insect Trogossitarii : and Mr. W. S. Mac- 

 Leay's family Engidae, as he has sketched it in the 1st part 

 of the " Annulosa Javanica," would comprehend our Corti- 

 caridae. 



Since it requires a correct combination of genera to form 

 a natural family, a more difficult task cannot fall to the lot of 

 the entomologist, until the whole group on which he is writing 

 has been carefully investigated ; and for this reason I have 

 omitted the families in the " Guide to an Arrangement of 

 British Insects." In the present instance I have separated 

 those tetramerous insects which live beneath the bark of trees, 

 and have characterized them by the term Corticaridag ; and 

 this family will comprise the genera between Scydmsenus 

 (which I believe to be closely allied to this group) and Hypo- 

 phlaeus. 



The pretty insect, which is the type of the genus Bitoma 

 (called sometimes Ditoma, by mistake I apprehend), has .been 

 frequently described and figured : it had not, it appears, been 

 detected in England when Mr. Marsham published his " Co- 

 leoptera." But a few years after, Mr. Haworth captured two 

 specimens at Little Chelsea, in July. It has subsequently been 

 found under the bark of trees, in May, June, July, and Au- 

 gust ; and I have twice met with it in considerable abundance 

 under the bark of beech-trees, in the New Forest. 



The plant is Origanum vulgare (Wild Marjoram). 



