THE RHYNCHOPHORA, OR WEEVILS. 197 



in the thorax (Plate XII, Fig. 6 a ; head and thorax of 

 Hylesinus vittatus] , and produced into the suggestion of 

 a rostrum in front ; the antennae (which have never more 

 than ten joints) elbowed, having a long basal joint, and 

 a more or less flattened club, which is either solid or 

 four-jointed; the front coxae globose, prominent, and 

 not widely separated ; the tibise flattened and widened 

 at the apex, hooked at the extremity, fossorial, and 

 usually toothed or crenulated on the outer side; the 

 mandibles short, robust, prominent, and triangular ; the 

 maxillae thin, broad, and spined internally, with their 

 palpi minute and conical ; the labrum obsolete ; the eyes 

 vertically oblong, and the third joint of the tarsi bi-lobed, 

 except in Tomicus and Platypus. 



All the species are small, mostly black or dull brown 

 in colour, and usually somewhat oblong, or cylindrical 

 in shape, being especially convex on the upper side. 



Many of them are very destructive to trees; their 

 larvae eating irregular galleries at right angles from a 

 straighter central line; and it is from their habit of 

 always engraving this kind of pattern in their devasta- 

 tions that some of them have been termed " Typogra- 

 phers." 



The small, dull black, elongate, cylindrical species of 

 Hylastes occur in profusion in the tracks eaten by their 

 larvae under the bark of decaying or felled pine-trees ; 

 they have the club of the antennae scarcely flattened, the 

 tibiae distinctly spurred at the apex, and the prosternuin 

 excavated in front; whilst in Hylurgus piniperda, a 

 larger, more robust insect, found sometimes in still 

 greater profusion, and very injurious to fir-trees, this 

 excavation is obsolete. 



The Hylesmi have an elongate oval club to the an- 



