60 [Marcli, 



legs are sulBcieut to distinguish it from all other British species vvith 

 dilated fore-metatarsi in Sections C and D, with the exception of one 

 to be described later on under the name of tnrsaUs. This also has 

 yellow legs, but besides being in a different Section (D), it has bare 

 meso-pleura?, a shining frons, and yellow halteres 



Armnta^ n. sp. Scarce. A few, representing both sexes, have 

 been ])icl<ed up in Stoke and neighbouring woods in August. The 

 angle at which the inner branch of the 2nd thick vein enters the 

 costa may vary to some extent as do most of the characters in one 

 species or other in a huge genus like this ; yet it is a character not to 

 be despised, and the best way undoubtedly of estiuiating it is by com- 

 parison with the angle made by the 1st thick vein. Under it the 

 species in this group range themselves thus: — With the angle much 

 larger than that of the 1st thick vein, or nearly a right angle, crassipes, 

 rudis, affinis, and collini ; roughly equal to it, armntn^tequalu, ciliafu, 

 propinqua, surdifrons, glnhrifrons^ and minor; or intermediate between 

 the iwo, parva, mallochi, uli(/inosa,Jlavfi, awAJlavesccns. 



liiidis, n. sp. By no means conmion, yet 1 have taken it spar- 

 ingly each month from J dy to October inclusive, Stoke Wood being 

 almost its only locality. The male may be readily recognised by its 

 large antennae and characteristic genitalia. In the series are two 

 specimens in which the costal fringe is distinctly longer than in the 

 type, and may fairly be called moderately long— so long in fact that 

 at one time 1 treated them as a distinct species belonging to the long- 

 fringed division. The point which first drew attention to the error 

 was the striking similarity in the two forms of the very distinctive 

 subanal body. And when on further comparison agreement was 

 found in all points save the fringe, no question of their identity 

 remained. The fringe I had always considered one of the most stable 

 of characters, and its instability here came as a surprise. Yet it only 

 shows how next to impossible it is to find a character, however con- 

 stant in the main, which may not on occasion deviate from the rule. 



Affinis, n. sp. More common than rudis, and in more numerous 

 localities, with a preference for wet places, such as Middle Park Pool, 

 Yackhill Marsh, &c., from -luly to September. In this species as 

 well as in 7'udis the proportions of the costal divisions vary more 

 than usual and independently of sex, the 1st division being some- 

 times not quite twice, and sometimes rather more than twice, the 

 length of the 2nd. 



