194 [August, 



7 (8) Anterior femora pectinate beneath ; basal joint of middle tarsi tangled ; 



middle tibia} remarkably dilated and ciliated 3. scambus Fall. 



8 (7) Front femora not pectinate beneath. 



9 (10) Posterior femora pectinate beneath 4. curvipes P&\\. 



10 (9) Only middle femora pectinate beneath 5. loripes iia.\. 



11 (6) Basal joint of middle tarsi much longer than second joint. 



12 (13) Middle femora and tibiae with rather long pectination. ..6. armaiu/i Zelt. 



13 (12) JVIiddle femora and tibiae minutely pectinate, almost simple... 



7. pectinulatus Lw. 



14 (1) Legs altogether simple (conf. C. pectinulatus) ; antennae orange at base... 



8. picticoriiis Zett. 

 Several more species are likely to occur in Britain. 



1. G. ma(/ms Lw. : on July 9tb, 1894, I took a pair of this extra- 



ordinary species at Bawdsey, near Felixstowe. It was first 

 described by Loew from Sicily, and be was blamed by 

 Gerstaecker for making a new species from a fly whose legs 

 were deformed by fungoid growth ! It has also been taken 

 near Vienna, and is probably a very widely spread species, 

 but suitable localities tor it are very uncommon, such as 

 broad mud flats on which herbage and small pools exist at 

 low tide, while the sea covers them at high tide. 



2. 0. pusillus Meig. : very uncommon. I caught a male at Lynd- 



hurst on June 26th, 1872, and Haliday caught it in Ireland. 



3. 0. scambus Fall. : not so common as some of the following species, 



but I have taken it from Penzance to Aberdeen, and 

 Mr. F. Jenkiuson has taken it at Scilly. The middle legs of 

 the male are very remarkable. 



4. C. curvipes Fall. : the commonest species of the genus, occurring 



everywhere in suitable localities from at least Slaptou Leigh 

 to Aberdeen. Some specimens from Chippenham Fen are 

 large and very dark legged. 



5. G. loripes Hal. : only less common than G. curvipes from at least 



Lyndhurst to Sunderland. It is remarkable how seldom 

 this common British species has been observed on the 

 Continent. 



6. C. armatus Zett. : I have not often met with this species, but I 



have taken it from Bournemouth to Nairn, and always on 

 the coast near salt water. Some specimens taken at Aber- 

 lady on June 23rd, 1884, where it was very abundant, have 

 the legs almost black or black-brown, the front and hind 

 femora being brownish but the front coxae always luteous. 



