Rhodites nervosus. 



This very interesting gall is one which, although by no 

 means uncommon, is not so very frequently seen by the casual 

 observer of the hedgerows. Like R. eglanterice, it grows with 

 much greater frequency on the under surface of the leaflet 

 than on the upper surface, remaining hidden until searched for ; 

 or the leaf is on a twig at a level somewhat above a person's 

 head. But a careful search and turning over of the stems of 

 a rose-bush in a hedge will usually reveal a few of these galls. 

 As regards size, they are a little larger than those of the 

 preceding species, and can be distinguished from them by the 

 peculiar thorn-like projections which grow upon the surface, but 

 cannot be detached, as a thorn may be, from a stem. These 

 thorns, or spines, vary in numbers from two to seven, and are 

 usually as many millimetres long as the gall is in diameter. 

 The galls are more frequently attached to the mid-vein of the 

 leaflet than to any other portion. They are found in such a 

 variety of situations as those of R. eglanterice. The leaflets 

 are neither deformed nor stunted in growth by the presence 

 of the galls, however numerous. The point of attachment is 

 not visible on the upper surface of the leaflet. The interior is 

 very roomy, the larva or pupa having plenty of space sur- 

 rounding it. The wall, or shell, of the cell is seldom more 

 than I mm. thick. When the galls of this as also those of 

 the former species are attacked by the inquiline Pcridistus 

 canincE, the interior is divided into several compartments. 



The illustration is of specimens gathered at Hastings by 

 the author. 



258 



