WALKER ON DIPTEEA OP AEU ISLANDS. 105 



outward towards its fore end, parted by about half its length from the 

 border, and by much less than its length from the flexure of the prse- 

 brachial; alulae blackish. Female. Head with a silvery white vertex, 

 frontalia deep black, linear. Length of the body bQ lines ; of the wings 

 10-12 lines. 



99. MuscA MARGiNiFERA, n. s. (gcnus LuciUa, Desv.) Fcem. Viridi- 

 cyanea, capite albido frontalibus atris, antennis pedibusque nigris, 

 abdominis segmentis purpureo marginatis, alis cinereis basi subnigri- 

 cantibus, alulis cinereis. 



Female. Greenish-blue. Head whitish, frontalia deep black, linear, face 

 and third joint of the antennae cinereous ; abdomen with a purple 

 band on the hind border of each segment ; legs black ; wings grey, 

 almost blackish at the base, praebrachial vein forming a hardly 

 obtuse angle at its flexure, between which and its tip it is hardly 

 curved inward, discal transverse vein nearly straight, parted by about 

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

 from the flexure of the prsebrachial ; alulae cinereous. Length of the 

 body 4^ lines ; of the wings 9 lines. 



100. MuscA BENEDiCTA, u. s. (gcuus Pyrellia, Desv.) Mas. Aureo- 

 viridis, capite albo, antennis pedibusque nigris, alis cinereis basi sub- 

 luridis venis basi fulvis, alulis testaceo-cinereis. Var. ? Abdominis 

 apice purpureo. 



Male. Golden green. Head white in front ; antennae and legs black ; 

 wings cinereous, slightly lurid towards the base, veins tawny towards 

 the base, praebrachial vein curved at the flexure, almost straight from 

 thence to the tip, discal transverse vein slightly undulating, parted 

 by full half its length from the border, and by little less than its 

 length from the flexure of the praebrachial ; alulae cinereous \Yith a 

 testaceous tinge. Var. ? or a distinct species : darker ; abdomen purple 

 at the tip. Length of the body 3 lines; of the wings 6 lines. 



101. MuscA OBTRUSA, u. s. (gcuus Pyrellia, Desv.) Mas et Fcem. 

 Purpureo -cyanea, antennis pedibusque nigris, alis cinereis, alulis ob- 

 scurioribus. 



Very nearly allied to M. refixa and to M. perjixa, but difi'ering slightly 

 in the veins of the wings. Male and Female. Blue, more or less 

 mingled with purple. Head black, slightly cinereous in front ; an- 

 tennae and legs black; wings grey, veins black, praebrachial vein 

 forming an almost angular curve at its flexure, nearly straight from 

 thence to its tip, discal transverse vein very slightly undulating, 

 parted by little more than half its length from the border, and by 

 about its length from the flexure of the praebrachial; alulae dark 

 cinereous. Length of the body 2|^-3 lines ; of the wings 5-6 lines. 



102. Musca domestica, hinn. See Vol. I. p. 128. 



103. Musca obscurata, n. s. Fcem. Nigra, subcinerascens, capite 

 postico albo, thorace vittis quatuor angustis nigris, abdomine tessel- 



