202 STRATIOMYID^ 



This species varies a little in the coloring of the legs, but never in such 

 a mantier as to be confounded with B. davipes ; a male caught in company 

 with normal specimens at Aberlady has the tibise all black except the 

 1)asal third of the anterior pairs and just the base of the hind pair, while 

 the hindmargins are slightly darkened until on the fifth and sixth segments 

 narrow blackish bands occur almost as in B. davipes; males taken at 

 Porthcawl in Glamorgan in 1906 have (like males of B. genicnlata taken 

 there at the same time) a much more blackish hue to the wings without 

 any trace of brownish. The only allied European species is B. davipes, 

 which in the female has dark wings and the male has a pale -haired 

 abdomen, while both sexes have much paler hind tibise and also have black 

 cross-bands on the abdomen just before the hindmargins of the segments. 



B. vallata is fairly common in Britain as I have numerous localities 

 from Penzance to Golspie, including Porthcawl and Llangollen in Wales, 

 and Colonel Yerbury took it in Co. Kerry. Colonel Yerbury has noted 

 that he caught a male "hovering" at Porthcawl on July 7, 1906. My 

 dates range from June 6 to August 26. It is recorded from North and 

 Middle Europe. 



Synonymy. — Forster apparently described his Musca vallata from the female 

 only, and probably what he called M. davipes from the male only, but ever since 

 Meigen accepted Forster's distinctions in 1820 there has been no doubt about the 

 two species, and no proof can now be brought forward to disturb the nomenclature. 

 Jaennicke's contention (Berl. Ent. Zeitschr., x., 234, 1866) that B. davipes is a variety 

 of B. vallata is proved to be a fallacy, and he also seems to have had an idea that 

 Forster (1771) had a priority over Linne (1767). 



2. B. clavipes Linne. Abdomen reddish orange with narrow black 

 cross-bands near the hindmargins of the segments; abdominal pubescence 

 of the male all yellow. Hind tibise hardly darkened at the tip in either 

 sex. Wings dark brownish black in both sexes. 



Very much like the preceding species. 



$. Distinguished from B. vallata by being slightly larger, and having narrow 

 black cross-bands on the depressed lines near the hindmargins of the abdominal 

 segments in both sexes ; basal segment in the male more narrowly orange on 

 the hindmargin ; the black cross-bands do not touch the hindmargins and do 

 not extend out to the sidemargins ; hindmargin of sixth segment and all the 

 seventh segment not blackened ; pubescence on the abdomen all yellowish. 



Legs in both sexes Avitli the hind tibiae hardly darkened at all about the 

 tip, or only slightly so, and with the ciliation on their inner side pale ; basal 

 joint of the hind tarsi considerably dilated, and distinctly longer than the 

 next four together. 



Wings more blackish, especially about the base, and consequently the 

 stigma less distinct. 



9 . Distinguished from B. vallata by many of the characters mentioned under 

 the male as applying to both sexes, and by the strongly blackish tinged A\dngs 

 which conseciuently have the stigma inconspicuous. Frons rather broader. 

 Antennae rather longer. Basal joint of the hind tarsi not much dilated, but 

 still longer than the next four joints together. 

 Length about 5-5 to 7 mm. 



This species varies a little in the amount of darkening about the tip of 

 the hind tibise, as it often has no darkening whatever or at other times 

 the tip is decidedly darkened but never to the extent that it is in B. vallata. 

 There is no other allied species known in Europe. 



