1920.] 273 



depression. Leg's with tarsi (especially the hind ones) distinctly darlier and 

 the knees only narrowly yellowish. Hind trochanters with only a hair or two 

 in place of the short spines of littoralis. 



$. Frons all dusted greyish (though the actual ocellar triangle i* not ver}' 

 densely dusted), evenly concave about middle, and with a single linear central 

 TuiTow ; whereas in littoralis t\\G frons is considerably shining blacldsh on upper 

 lialf, and thert. are two separated shallow furrows on at least the front part of 

 this blackish half, while the dusted front half begins with a distinct prominence. 

 Thorax and abdomen much as in the male. Aculeus longer in proportion to the 

 basal part than in littoralis and perfectly straight, whereas in litturalis it is 

 slightly recurved. Legs coloured as in the male, while the anterior femora bear 

 tiuv spines at tlie base beneath, which are much shorter and paler than in 

 littoralis. 



Length 2-2'5 mm. 



Described from tliree males and two females caught by myself at 

 Blakeney Point, Norfolk, on July 17th and 20th, 1920, where they occurred 

 in company Avith littoralis among the Psamvia growing on the sand- 

 dunes. 



Becker described P. minimus in 1S97 from a female in Loew's 

 Collection, but later (1900), liaving captured other specimens in company 

 with littoralis, came to the conclusion that minimus was only the female 

 of littoralis. It is, however, quite certain that minimus $ witli an 

 entirely dull frons cannot be the true female of littoralis, this latter 

 being- probably unknown to Becker. I therefore use the name minimus 

 for the Blakeney specimens, in spite of the fact that there may be some 

 doubt of their identity with the type, owing to the latter being described 

 as having pale tarsi. 



3. P. cilitarsis Strobl. Mitt. Nat. Ver. Steiermark, xlvi, p. 113 

 (1909). 



(^ . Clo5:ely resembling sylvaticvs, but undoubtedly distinct. Thorax 

 perhaps a little more shining. First abdominal segment not so dull. The 

 abdominal pubescence short and scjittered on the second to fourth segments, 

 but longer and very distinct on the fifth, especially toAvards the hind-umrgin. 

 Ilypopygium as in i<ylvaticu^,\\\t\\ a diagonal groove or fold beginning above on 

 the right. Terminal lamellae of genitalia somewhat translucently yellowish, 

 their tips Ij'ing in a semicircular excision in the hind-margin of the fourth 

 ventral segment. Legs coloured as in sylcativus, but the tarsi often obscured; 

 bind tibiae more conspicuously bent and twisted, hind tar.^^i longer, the first two 

 joints with a distinct ciliation of black hairs above or slightly postero-dorsally. 



5 . Resembling sijhaticvs, but ratl.er larger. Frons more widene.l out 

 about middle and not shining for so long a distance at sides above. Abdominal 

 pubescence hardly so long. Ilypopygium with a rather longer basal part, and, 

 in consequence, the aculeus shorter in proportion and rather more slender 

 than in sylvaticKS. Hind tibiae rather more bent and_ twisted. Tarsi rather 



