3 14 Mr, F. Walker's Characters of undescrihed Diptera 



half its length from the border and by more than its length from 

 the flexure of the praebrachial ; alulae grey. 



Length of the body 4 lines; of the wings 9 lines. 

 Mexico. 



Genus Musca, Linn. 

 Musca sensifera. 

 Mas. — Nigra, cinereo-tomentosa, capite alho, frontalibns atris 

 antice latescentibus, palpis antennisque fulvis, thorace vittis 

 tribus nigris, abdomine basi nigro-piceo, fasciis duabus canis, 

 alis cinereis, venis fuscescente nebulosis, vena prffibrachiali 

 angulum rectum fingente, vena discali transversa undulata. 

 Male. — Black, with cinereous tomentum : head white ; fron- 

 talia deep black, widening in front; proboscis, palpi and antennee 

 tawny ; third joint of the antennae rather short, not reaching the 

 epistoraa ; thorax with three black stripes ; abdomen piceous, 

 black towards the base ; second and third segments with hoary 

 bands on the fore borders ; wings grey, brownish along the black 

 veins; praebrachial vein forming a well defined right angle at its 

 flexure, slightly curved inward from thence to the tip, which is 

 a little in front of the tip of the wing ; discal transverse vein un- 

 dulating, parted by less than halfits length from the border and by 

 more than half its length from the flexure of the praebrachial ; 

 alulae greyish white. 



Length of the body 4^ lines ; of the wings 10 lines. 

 Mexico. 



Musca perlata. 



Fcem. — Obscuie cyanea, setosa, sat gracilis, capite albido, fron- 

 talibns obscure nigris, palpis antennis pedibusque nigris, 

 thoracis vittis quatuor pectoreque albidis, abdomine fasciis 

 duabus latis albidis, apice rufescente, alis sub-cinereis, basi 

 vittaque costali lata nigris, vena praebrachiali angulum rectum 

 fingente, vena discali transversa subundulata. 

 Female. — Dark blue, bristly, rather slender : head bla^k, with 

 whitish tomentum ; frontalia dull black, widening in front ; palpi 

 and antennae black ; third joint of the latter slender, reaching the 

 epistoma; thorax with four whitish stripes; pectus whitish; ab- 

 domen with two broad whitish bands ; tip reddish ; legs black ; 

 wings greyish, black at the base, and with a broad black costal 

 stripe; preebrachial vein forming a well defined right angle at its 

 flexure, near which it is curved inward, and is thence straight to 

 its tip, which is somewhat in front of the tip of the wing ; discal 



