DONISTHORPEA. 237 



bus ; femina paulo minor, pilositate sparsa fere obsoleta, pilis minutis hinc 

 inde sparsis, pubescentia microscopica cinerascenti-sericea aeque densa ac 

 in F. flava et umbrata, oculis hirtulis, alis albescenti-hyalinis a basi fere ad 

 medium dilute brunnescenti-tinctis, nervis pallidis, apicalibus omnino dilutis, 

 stigmate cinerascenti-pallido, area discoidali trapezoidea dimidio minori h.e. 

 proportione eadem ac in F. nigra $, anticis 8 millimetra longis, squama 

 subrectangulari supra integra, abdomine minori angustiori, pilis sparsis 

 tantum minutissimis, multoque rarioribus, igitur longe nudiori (pube tamen 

 sericea, ut dictum, in ambis aequali) ; mas corpore paulo minus nitido, pube 

 sericea distinction, oculis parce microscopice hirtulis, lineola frontis impressa 

 longitudinali distincta at transversa nulla, alis sicut in femina, nonnihil 

 dilutius coloratis, area discoidali proportione ut in F. nigra $ (igitur dimidio 

 minori quam in mare F. umbratae), anticis fere 5| millimetra longis. Color 

 alarum in specie praesente medium tenet inter F. umbratam et F. flavam, 

 dilutior est quam in ilia, obscurior quam in hac. His notis speciem earn 

 solummodo indigitare valui. F. rubra Zett. Ins. Lapp. 450, 8 et Dahlb. 

 mscrpt. probabiliter commixta est e speciebus tribus memoratis affinibus ; 

 sub hoc nomine etiam easdem tres a Cel. Dahlbom accepi. Maris varietas b., 

 quae in Ins. Lapp, exponitur, verus est mas F. flavae nostrae ; var a. ibid. 

 et F. umbratae et flavae pertinere videtur. At observationibus ulterioribus 

 praesertim in vivo nidoque factis termini naturales, quibus circumscribuntur 

 hae species, clarius elucebunt. Forsitan haud inconvenienter simul cum 

 F. nigra propriam constituere possint subdivisionem, parvitate marium 

 proportione feminarum suarum, inter alia signa, dignotam." 



Habitat. 



Donisthorpea mixta ranges over North and Central Europe ; 

 Ruzsky records it from the Caucasus, Siberia, and Finland, and in 

 North America it is represented by the var. aphidicola Walsh, which 

 according to Wheeler is the most abundant form of the umbrata 

 group in the Northern States. 



It is distributed in Britain as follows : 



Devon, S. : Bickleigh (Bignell) 15 ; Devon, N. : Lundy Island 

 ( Donisthorpe) 2 6 . 



Somerset, N. : Long Ashton and Leigh (Smallcombe) . 



Dorset : Glanvilles Wootton (Dale Coll.). 



Isle of Wight : The Landslip (Dale Coll.). 



Kent, E. : Deal (F. Smith) 5 ; Herne Bay (Rothney Coll.). 



Surrey : Richmond Park (Dollman) 20 ; Mickleham (Crawley and 

 Donisthorpe) 20 ; Box Hill 27 and Weybridge 20 (Donisthorpe). 



Essex, N. : Colchester (Harwood) 25 . 



Oxfordshire : Shotover Hill (Hamm) ; Horsepath (Cambridge 

 Mus. Coll.). 



Bucks : Bourne End (Best Gardner)**. 



Suffolk, E. : Pakefield ( F. Smith) 8 . 



Gloucester, W. : Dursley (Smallcombe). 



Glamorgan : Dinas Powis 28 , Cwrt-yr-ala 25 , Southerndown, Porth- 

 cawl, and Penarth (Hallett). 



Edinburgh : Dalkeith Park (Evans) 22 . 



Linlithgow : Dalmeny Park (Evans). 



Fife and Kinross : Isle of May (Baxter and Rintoul) 19 . 



