_Female._ Black, with cinereous tomentum. Head gilded in front, clothed behind and beneath with tawny hairs, frontalia deep black, hardly widening towards the face; thorax with three black very distinctly marked stripes, the middle one dilated on the scutellum; abdomen distinctly tessellated with six large cinereous excavated spots; wings grey, praebrachial vein forming a right angle at its flexure, near which it is much curved inward, and is thence straight to its tip, discal transverse vein hardly undulating, parted by much less than its length from the border, and by little more than half its length from the flexure of the praebrachial; alulae white. Length of the body 5 lines; of the wings 10 lines. 93. SARCOPHAGA INVARIA, n. s. _Mas et Foem._ Nigra, cinereo-tomentosa, capite _maris_ albo, thorace vittis quinque nigris, abdomine tessellato, alis cinereis. _Male and Female._ Black, with cinereous tomentum. Thorax with five black stripes, the lateral pair incomplete; abdomen distinctly tessellated, the spots being much excavated; wings grey, praebrachial vein forming a right angle at its flexure, near which it is much curved inward, and is thence straight to its tip, discal transverse vein hardly undulating, parted by much less than its length from the border, and by rather more than half its length from the flexure of the praebrachial; alulae white. _Male_. Head silvery white, frontalia deep black, linear; tomentum of the thorax and of the abdomen more whitish than that of the female. _Female_. Frontalia slightly widening towards the face. Length of the body 4--4-1/2 lines; of the wings 8 lines. Subfam. MUSCIDES, _Walk._ Gen. IDIA, _Meigen._ 94. Idia australis, _Walk. Cat. Dipt._ pt. 4. 809. Inhabits also Australia. 95. IDIA AEQUALIS, n. s. _Foem._ AEnea, capite subtuberculato, thoracis lateribus pectoreque albido-testaceis lineis duabus lateralibus aeneis, abdomine fulvo fasciis tribus aeneis, pedibus testaccis tibiis apice femoribusque aeneis, alis cinereis apice nigricantibus. _Female._ AEneous-whitish, testaceous beneath. Head with minute tubercles on each side of the front, frontalia piceous, linear; thorax with an aeneous stripe on each side in a line with the base of the wings, and with numerous points between these lines and the disk; abdomen pale tawny, with three aeneous bands on the hind borders of the segments; legs testaceous, tibiae towards the tips and femora aeneous; wings greyish, with blackish tips, praebrachial vein forming an obtuse and much-rounded angle at its flexure, from whence it is almost straight to its tip, discal transverse vein parted by about half its length from the border and by about its length from the flexure of the praebrachial; alulae very slightly cinereous; halteres testaceous. Length of the body 3-1/2 lines; of the wings 6 lines. Gen. MUSCA, _Linn._