274 [December, 



browiiisli, liiiul tarsi witli basal joints not ciliated, the other four joiiits witli 

 longish hairs above but hardly ciliated. Anterior femora with a ]'.air of tiny 

 black spines at the base beneath, and hind trochanters with 2-3 tiny bristles 

 at base beneath, all very much as in sylvaticus. 



Length fully 3 mm. 



Two males in the Verrall Colle<^tion (separated off from sylvaticus 

 under the MS. name of i^ilitarsis) taken by Col. Yerbury at Erodio 

 (Elgin) on August 7th, 1905. The same collectoi- also captured another 

 male at Nethy Bridge (Inverness) on July 28th, 1911. In the 

 Cambridge University Museum there are five males and a female taken 

 by Mr. F. Jenkinson at Logie (Elgin) in August 1908. 



4. P. sylvaticus Mg. I have nothing to add to the description in 

 "British Flies." The vav.? mentioned by Verrall is my flavitarsis , 

 and is at once distinguished by the bare hind trochanters. 



5. P. geniciilatus Mg. Verrall was undoubtedly wrong in con- 

 sidering his ffenictilatns as being the same as nigritnlus. His P. geni- 

 culatns has olivious abdominal pubescence, though this is not so long on 

 last segment as in sylvaticus and pilifavsis. A distinguishing character 

 in the male lies in the delicate eiliation of outstanding pale hairs on the 

 postero- ventral surface of hind femora. The frnns of the female is not 

 brightly shining above ; the aculeus reaches to the end of the first 

 abdominal sternite ; the anterior femora are armed beneath at the base 

 ^ith 1-2 small bristles, the hind trochanters may bear a few short hairs 

 but not bristles, the tarsi are dark, and the ungues and pulvilli ver}" large. 



A further examination of Meigen's types will be necessary to decide 

 whether his species was geniculatus of Verrall or the next species (nigri- 

 tulus Zett.) ; this latter being unrecognised by Verrall at the time he 

 examined these t^^pes. 



6. P. nigrituhis Zett. Dipt. Scand. iii, 957 (1844). 



TxQSumhlm^ yeniculattis (Mg.) A'err., but hind femora of male without tlie 

 pestero-ventral eiliation ; anterior femora of female unarmed at the base 

 beneath and all the ungues and pulvilli short as in the male. 



c?. Thoracic pubescence shorter than in geniculatus. The tiny abdominal 

 bristles more numerous on 2nd-4th segments, but very little longer on tin- 

 long fifth segment tlian elsewhere. Hypopygium smaller, the membranous 

 depression large. A good distinguishing character lies in the dense velvety 

 pile with which the 3rd and 4th abdominal sternites are clothed, these sternit>'.s 

 being quite bare in (/enicuJatus, Legs with only the knees pale ; hind trochan- 

 ters unarmed, but apparently bluntly produced postere-ventrally, owing to the 

 presence of a dense patch of pile. Hind femora with only the normal tiny 

 hairs postero-ventrally. 



