On Mii^ca margliialis and tJie Genus Pycno3oma. 301 



XXXVIir. — Si/nont/mic N^ofes on Musca marginalis, IVied., 

 and the Genus Pycnosoma, Br. cC; von Berg. By 

 Eknest E. Austen. 



Like many another nmcli-coUected species, Muscaviarginnlis^ 

 ^Vi('(l., one of the coininonest and most striking of African 

 I\Iiisci(ls, lias had the misfortune to be mucii and variously 

 described. In 1894, however, Brauer and von Bergenstamm 

 fixed its system;itic position by making it the type of their 

 new genus Pi/cnosoma, the synonymy of which is as 

 follows : — 



Pycnosoma, Br. & von Berg. 



Pi/enofoma, Brauer and von Borgoiistamin, Denkschr. math.-naturwiss 



'Cl. k. Akad. Wi>>s. ]M. Ixi. (18i)4) p. r,23. 

 Cosminn, Iu)bineiiii-I)>isvoidy, Essai siir le.s .Myodaires (1839), p. 423. 

 C/iri/s>nn/a, Koliineau-Desvoidy, W>(V/. p. 444 [pro parte). 

 Somomyia, llondaiii, ^[ein. dell. Accad. dell. Scionze dell' Istituto di 



Holofjrna, t. xii. (IBiil) p. 44, note. 

 Pwacnmpfomyia, IJoiifrli, Proc. Acad. Nat. Sci. Philadelphia, 1898, 



p. 184. 



Brauer and von B('rgcii5!tamm [loc. cil.) defined the genus 

 Pi/cnosoma as — *' Call<i])h()rin3e, which have sternopleural 

 bristles 1, 1 ; which exhibit a row of (often fine) hypopleural 

 bristles, and in which the bristles of the dorsum of the thorax 

 are frequently not developed. Female with orbital bristles, 

 but these often small. In the male the upper facets of the 

 eyes are fnquentl)^ eidarged. 'i'yP^ marginalis, Wied. : 

 Afiica." SubsequcMitly (Sitzgsber. k. Akad. Wiss. matli.- 

 iiaturw. Cl., cviii. Bd., Abth. i. (18i)9) pp. 4l)G-407), Brauer 

 gave the following further characteristics of Pycnosoma: — 

 "Face hairy; body blue or green, metallic; facial angles 

 moderately high above the oral margin, clypeus less prominent 

 [than in Tlnli/chceta, Br. & von Berg.], facial keel small or 

 absent. Third longitudinal vein bare or .sometimes hairy 

 (Eastern hemi.^phire, India etc., Africa)." 



Cosmina, Itob.-Desv., must be cancelled as insufficiently 

 characterized. Of the three species described {loc. cit.) by 

 Robineau-Desvoidy, one is mentioned below as possibly 

 identical with Pycnosoma marginnle {Musca marginalis), 

 Wied., while the other two are probably also synonyms of 

 one or other of Wiedemann's species described under Afusca 

 and now assigned to Pycnosoma. 



Ann. i; Mag. N. Hist. Ser. 7. IV. xvii. 21 



a 



