MELA>'QSTOMA. ASARC1XA. 21 



13. Melanostoma annulipes, Macquart (1842). 



A very variable species, but easily recognised by its black-ringed 

 legs and short abdominal spots. 



The species varies in the colouring of the legs, the hind pair 

 being sometimes mainly black, and in the shape of the yellow 

 abdominal spots, those on the second segment being often wanting. 

 It is the predominant African species, which seems to replace 

 the Palsearctic scalar e. The length of the bodv varies from 

 7 to 9 mm. ; the essential characters are the bare arista, the 

 annulated legs, and the yellow abdominal spots being not longer 

 than half the segment which bears them, and usually much shorter, 

 chiefly in the female. 



The collection contains the following forms : 



(a) annnlipss, Macq. Of this typical form there are specimens 

 from Marsabit, Brit, E. Africa, 21. ix. 1911 (R. G. Stordy) ; 

 Oshogbo, S. Nigeria, xi. 1910 (Dr. T. F. J. Mayer) ; Zungeru, 

 N. Nigeria, 15. xi. 1910 (Dr. J. W. S. Macfie) ; Obuasi, Ashanti, 

 28. vi. 1907, "caught hovering over stream" (Dr. W. M. Graham). 



(b) automenes, Walk. (+ annu latum, Big., -f pyropJicenoi cles, 

 Speis.). Two male specimens from Obuasi, Ashariti, 4. viii. 1907 

 and 7. xi. 1907 (Dr. W.1L. Graham). 



(c) mauritianum, Big. ( + gymnocerum, Big.). Three females 

 from Obuasi, Ashanti, 15. vii. 1907 and 22. x. 1907 (Dr. W. M. 

 Graham), which agree better with gymnocerum. A couple from 

 Mahe, Seychelles Islands, ix. 1908 (Hugh Scott), are typical 

 mauritianum. 



14. Melanostoma infuscatum, Becker (1910). 



Easily known on account of its black antennae and legs and 

 general very dark colouring ; perhaps only an extreme form of the 

 preceding species. 



Three males and one female from Mt. Chirinda, Southern Rho- 

 desia, vi. 1911 (C. F. M. Swynnerton), which have yellow knees 

 on the hind legs, while the female has mainly yellow fore legs ; 

 length 7-5 to 8 mm. Two males from Brit. E. Africa, E. side of 

 Aberdare Mountains, 7,300 ft., 2-4. ii. 1911 (T. J. Anderson), are 

 of somewhat larger size (9 mm.) and have entirely black hind 

 legs, while a female from the same locality and collector has 

 entirely black antennae, but mainly } T ellow legs. 



Genus 4. ASARCINA, Macquart (1842). 



On this interesting genus I have published two papers, in 1903 

 and 1908 *, which have been criticised by Dr. Speiser in his work 



* " Di una specie inedita di Ditteri Italian! appartenente ad un genere 

 nuovo per la Fauna europea," Bull. Soc. Entom. Ital. xxxv. pp. 3-19 (1903). 



" Secondo contribute) alia conoscenza del genere Asarcina," Ann. Mus 

 Nation. Hungar. vi. pp. 495 504 (1908). 



