PITYOGENES IN SCOTTISH WOODLANDS. 103 



excavated surfaces : they are smaller and more numerous, 

 however, on the rear portion of the wing-cover. The suture of 

 the wing covers is raised, and on each this raised inner boundary 

 runs along the whole length. In the anterior two-thirds of the 

 dorsal surface of the wing-cover there is a shallow furrow which 

 runs below the raised inner boundary. This furrow widens out 

 into a triangular depressed area distinct from the apical excava- 

 tion already referred to. This area is of importance in connec- 

 tion with the position of the prominences which distinguish the 

 several forms. A distinct line of hairs runs along the wing- 

 cover within the raised inner boundary, and this line of hair is 

 easily visible on the apical excavation. 



The type of the species P. bide?itatus described by Eichoff is 

 that in which the only marked projection of the wing-covers is 

 a single hook on each, placed on the outer boundary of the 

 excavated apical cavity. The hook consists of a short heavy stem 

 and a head shaped somewhat like a Lochaber axe. Two stiff 

 bristles arise at the base of the hook, but when viewed from 

 some directions they may appear to rise from the points of the 

 head. The outer edge of the excavation below the large hook 

 is rough and carries a number of small tubercles ; hairs are 

 associated with the tubercles. The number of tubercles is not 

 constant, but four are usually easily seen ; two of these are 

 placed close to the tip of wing-cover and two are placed midway 

 between the base of the hook and the tip of wing-cover. The 

 tubercles do not appear to be all equally close to the edge of the 

 excavation. The way in which hairs are associated with these 

 is similar to the arrangement in the case of the hook. 



A varietal form of P. bidentatus has also been described 

 in detail. This variety has all the characters of the type 

 already described, but it has in addition a second small 

 hook placed on the true horizontal dorsal surface of the wing- 

 cover and in the triangular depressed area already referred 

 to as present in all forms. The shape of the second projection 

 is quite distinctly hooked, and the tip of the hook is turned to 

 the rear of the beetle. This second hook is not equally 

 prominent in all cases where it occurs, and on account of the 

 position in the triangular depression it is not quite so obvious 

 as the greater. Its position relative to the first described hook 

 is constant, as is the distance from the suture. 



In the two described forms of males, the rough hairy outer 



