J96 BRITISH BEETLES. 



seem to be nine joints in all ; their rostrum, also, is some- 

 what deflexed; their tibiae armed at the apex with a 

 stout external hook, and their tarsi slender. They are 

 all distinguished by a certain linear, parallel, flattish, or 

 cylindrical habit, pre-eminently adapted for boring in 

 wood, or existing under bark. 



Cossonus linearis (Plate XII, Fig. 5) is very local ; 

 but, when found, occurs in great profusion ; as, indeed, 

 is the case with most of this family. Mesites Tardii, 

 the largest, lives in the wood of ash -trees, etc., at Kil- 

 larney, Mount Edgcumbe, and elsewhere on the western 

 coast. It has very little the aspect of an English species, 

 and varies much in size. In the male the antennae are 

 inserted near the apex of the rostum, which is dull, en- 

 larged, and suddenly contracted behind their articula- 

 tion; whilst in the female it is smooth, narrow, and 

 with the antennse inserted close to the base. 



Some of the remaining species, small, obscure, cylin- 

 drical beetles, are common in half rotten wood, under 

 fir bark, etc. 



The remaining family, the Hylesinida (also termed 

 Scolytidte, or Tomicidte), are by some authors raised to 

 a sectional rank, under the name XyJophaga ; but, being 

 intimately allied to the Cossonida, they are generally 

 considered as a division of the Rhynchophora, connect- 

 ing that section with the next. 



These insects have been fully described by Erichson, 

 in Wiegmann's Archiv. fur Naturg., vol. ii., 1836 (an 

 abstract of which appeared in the ' Naturalist ' for De- 

 cember of the same year), and also (with others injurious 

 to timber) by Ratzeburg, 'Die Forst-Insecten/ Berlin, 

 1837, a work of considerable value. 



They have the head somewhat globular, deeply sunk 



