Bagnall and Harrison : Midge-Galls of Yorkshire. 339 



Fervisia geranii Kieff. Almost certainly this is an 'aggregate' species 



requiring careful study for its final elucidation. Redcar, on 



Erodium ; Middlesbrough, on Geranium sylvaticum ; Redcar, on 



G. molle. 

 P. hygrophila Mik. On Galium paliistre. Nunthorpe, Leeds District ; 



probably generally distributed. 

 P. inchbaldiana Mik. On Salix alba. Fairly general. 

 P. kiefferi Marchal. On ivy flowers. Middlesbrough and Gunnergate. 

 P. laricis F. Loew. On Larix decidua. Eston and Kildale. 

 P. lathyri Kieff. On Lathyrus pratensis. General. 

 Perrisia sp. Houard, 3776. With P. lathyri. 

 P. libera Kieff. On oak. Thinly but widely distributed in the Cleve- 



lands, and Leeds district. 

 P. loewiana'Ruhs. On Vicia sepiitm. Not uncommon. 

 P. lotharingiae Kieff. On Cerastium ; Redcar. 

 P. loticola Riibs. On Lotus corniculatus and L. major. Not uncommon 



in the Northern Clevelands. 

 P. malpighii Kieff. On Quercus. Near Leeds. 

 P. miki Kieff. On Centaurea nigra and C. scabiosa. Marton. 

 P. panieli'Kiefi. On oak. Common on one tree near Leeds. 

 P. periclymeni Riibs. On Lonicera Periclymenum. Great Ayton, Yarm, 



Bardsey . 

 P. plicatrix H. Loew. On crinkled leaves of various species of Rubus. 



Not uncommon, everywhere. 

 P. pustulans Riibs. On Spiraea Ulmaria ; not rare. In all old colonies 



of meadow sweet near Middlesbrough. 

 P. ranunculi Bremi. On leaves of various Ranunculi, chiefly R. repens. 



Generally not uncommon. 

 P. rhododendri Kieff. In the garden of our friend Lofthouse at Middles- 

 brough, on Rhododendron ferrugineum. 

 P. rosarum Hardy. In folded leaves of all wild roses ; ever5rwhere 



common, but preferring Rosa glauca forms. 

 P. rostrupiana Kieff. On Spiraea Ulmaria. Rare near Middlesbrough. 

 P. serotina Winn. On Hypericum near Leeds. 

 P. silvicola Kieff. On Stellaria Holostea, near Leeds. 

 P. spadicea Riibs. On Vicia sepium, not uncommon. 

 P. stachydis Bremi. On Stachys sylvatica and 5. palitstris. Not rare in 



the Clevelands. 

 P. thomasiana Kieff. On several species of lime. Gunnergate. 

 P. tortrix F. Loew. On plum and blackthorn. Near Leeds. 

 P. trifolii F. Loew. On Trifolium spp. Everywhere ; only needs 



careful searching. 

 P. tubicola Kieff. On Cytisus scoparius. On disused railway near 



Normanby . 

 P. ulicis Kieff. On Ulex europaeus. Eston. 



P. ulmariae Bremi. On Spiraea Ulmaria. Common everywhere. 

 P. idmicola Kieff. On Ulmus . Leeds district. 

 P. urticae Ferris. On Urtica dioica and U. urens. Exceedingly common 



everywhere . 

 P. veronicae Vallot. Generally on Veronica Chamaedrys and V. niontana ; 



rarely on other Veronicae. Plentiful. 

 P. viciae Kieff. On V . cracca, etc. Abundant. 

 Perrisia sp. In heads of Solidago. Not rare. 



Jaapiella volvens Riibs. On Lathyrus pratensis. Not uncommon. 

 /. cirsiicola Riibs. On flowers of Cirsium arvense. Fairly general. 

 Hartigiola annulipes Hartig. Forms a characteristic gall on beech leaves. 



Not very common, but still widespread. 

 Taxomyia taxi Inchbald. On Yew. Rare in the North ; Gunnergate. 



1921 Oct. 1 



