110 CMay, 



though with considerable white pubescence behind ; hind femora sometinios 

 with two preapical spines ; basal joint of front tarsi barely longer than second... 



lu. cotisubrina Zytt. 



20 (17) Front Ibmorii witlioiit w black ])ot!tiii!ition bi'iicatli. 



21 (21) Front coxa; and fcinorti with black pubesceiico ; outer lainollic long. 



22 (23) Beard wliitisli ; outer lumellEe not forked ; face narrow, black on all middle 



part ; middle coxio with stiff bristles almost like a small sjnne ; hind femora 

 with one small proapical spine ; liasal joint of front tarsi nearly as long as next 

 throe together, and bearing some short sijines beneath at or before the middle ; 

 abdomen rather silvery 1 1. micans Meig. 



23 (22) Beard black ; outer lamella; conspieuouslj forked ; face black ; basal joint of 



front tarsi Ijaroly longer than second ; abdon)en ncit at all silvery ; middle coxas 

 with a faint trace of a tuft of black bristles 12. vasuia Fall. 



24 (21) F" rout coxa) and femora with white pubescence; basal joint of front tarsi 



almost as long as rest together. 



25 (;;<>) Outer lamellsB moderately long and bent at a right angle ; hind femora with 



only apical lialf black ; posterior coxse slightly Wack bristly... 



13. riparia Meig. 



2G (25) Outer lamella? short and tuftetl ; middle cox;c with a .slight black fringe... 



14. penicillata Lw. 



If B. gravipes Wlk. is a disliiict species, it may be distinguished 

 from antennaia by its simple arista ; from spimcoxa,fascipes,pecfinaf a, 

 micans and nasuta by its white face ; from crassij)es, consohrina, riparia 

 and penicillata by its long lamellae ; from elegantula by its dull colour 

 and its single preapical s])ine ; from neworum and rivalis by its larger 

 size ; and consequently it is reduced to a comparison with P. patula, 

 to which it must at any rate be closely allied through its " dark brassy, 

 not shining " thorax on which are "two black stripes rather marked." 

 I am however not inclined at present to pronounce them identical, 

 because Haliday (in Walker) says nothing about a spur to the middle 

 coxse, and even if that allied it to P. Jongilamellata Kowarz, I can 

 hiirdly believe but that he would have used a stronger term for the 

 lamellae than simply "" elongatis,''' and I do not comprehend the hind 

 " metatarsus with a short spine above near the middle ;" the character 

 of "hind legs black" 1 consider of very little comparative value in 

 the males of this genus. 



1. P. antennata Carl. : very rare. 'Ihe British Museum possesses a 



recent male taken at Clifford's Castle, Herefordshire. P. 

 discigera IStenh. is very similar, but has no spine on the 

 middle coxae. 



2. P. spinicoxa Lw. : not at all uncommon on the leaves of shrubs at 



the sides of paths in woods in Sussex, Hants, and Kent. It 

 is easily known by its black face, spined middle coxae, and 

 forked lamellae. 



