1909.1 203 



Develops on both surfaces of leaf, but more frequently on the under than on 

 the upper surface. Situated principally on the midrib and its offshoots, not often 

 on the interspaces, but affects the petiole and young twig willi great frequency. 

 When on leaf and clustered together a considerable puckering of leaf-tissue often 

 results, the same also takes place when numerous and coalescent on midrib or vein. 

 The proportion of galls developing on the upper surface of leaf appears to be about 

 one to ten of those on the under sui'face. The gall also develops on the twig, where 

 it may be axillary or otherwise. Frequently 8-20 grouped together and coalescent 

 in leaf-axil causing the twig to be considerably deflected ; when one or two only in 

 same position they may be easily overlooked. Normally there is little swelling of the 

 twig where galls are situated, but the midrib and veins are sometimes much swollen. 

 The greater portion of the gall growth projects from the under surface, and consists 

 of the portion within which the larva lives, and upon which it subsists ; the other 

 part of the gall is in the form of a small rounded elevation situated on the upper 

 surface of tlie leaf and devoid of any opening. The shape of the gall is that of a 

 cylinder slightly constricted in its centre ; it also resembles a truncated cone, the 

 rim of which expands slightly, and, because of a deep cavity, produces a crater-like 

 formation ; the rim of the cone is rough and jagged. The outer surface of the gall 

 bears a few short hairlets similar to those on the leaf. The colour is a pale reddish - 

 brown, which becomes lighter when the gall is dry ; when the cone-like portion is 

 upon the upper surface of leaf its colour is much darker. The gall may be erect, 

 oblique, or adpressed to the leaf tissue, solitary or gregarious ; single or coalescent 

 at the bases ; sessile, with a relatively large spreading base. Apparently the rim 

 of cone is never coalescent with its neighbours. It appears to be always unilocular 

 and unilarval ; larva pupating (? in the ground). Its dimensions are : — height, 

 2 mm., diameter of base, 1"5 mm., diameter of aperture, 1 mm. Very numerous on 

 some leaves ; numbers varying up to 70 or more on a leaf, 12 cm. by 7 cm. 



This is a most interesting little gall. There does not appear to 

 be any British gall exactly like it. The nearest approaching to it 

 are those caused by Kormomijia corni, Gir., on leaves o£ Gornus san- 

 guinea, and those caused by Cecidomyia ulmariee, Brem., on leaf-segment 

 of Spirxa ulmaria, but neither of these is crater-like. 



Park House, Worksop, Notts. : 

 August, 1909. 



HELP-NOTES TOWARDS THE DETERMINATION OP BRITISH 

 TENTEREDINIDM, &c. (25). 



BY THE EEV. F. D. MORICE, M.A., P.E.S. 



DOLERIDES: L0DEBU8, Knw., and DOLERUS (in part). 

 The Dolerides are easily recognised as such, except in the case 

 of abnormal specimens, by the neuration of the fore-wing alone, 

 having (a) a divided I'adial cell, (b) the second cubital nerve absent ; 



