616 Prof. MariggBezzi's Report on a Collection of 
This species seems, however, to be decidedly variable. 
I have in my collection 9 f and 7 ? from Upper, Middle 
and South Italy, Sardinia and Corsica, Portugal, Greece 
and Syria. Of these specimens, ten have the appendix on 
the upper branch of third vein ; one has an appendix also on 
the inner side of the discal cell; twelve have the wings 
hyaline, the others infuscated ; two have the femora wholly 
or in greater part yellow. The female has normally the 
wings hyaline and the upper branch without appendix 
(five specimens out of seven), and the femora are more 
yellow. 
17. Petrorossia letho, Wiedemann (1828). 
Anthrax longitarsis, Becker (1902), from Egypt, is with- 
out doubt a synonym of this species, which seems to be 
widely spread in Africa. The female has no appendix at 
the fork of the third vein, hyaline wings and_ yellow 
femora; the male has also no appendix (but one has an 
appendix on the anterior angle of the discal cell), but the 
femora are wholly or partly black ; the wings are darkened 
in the basal half in two specimens and hyaline in one. 
Four specimens of both sexes from North Nyasa, 
Akamanga, South Rukuru River, October 10, 1909, and 
Songwe River, September 17, 1909 (Dr. J. B. Davey). 
‘The species is already known from Nubia, Sahara and 
Alexandria. 
Wiedemann records also the variable colour of the legs ; 
Loew in 1860 has it under Hxoprosopa, but in the “ Berlin 
Entom. Zeitsch.,” xvi. p. 77, he says that it is a species of 
Argyramoeba, near hesperus. 
18. Petrorossia fulvipes, Loew (1860). 
A single male from North Nyasa, Florence Bay, 
February 1, 1909 (Dr. J. B. Davey), of this elegant species, 
agrees very well with Loew’s description. The wings are 
strongly darkened on the basal half, the limit of the dark 
patch ruuning obliquely from the end of the first vein to 
the apex of the anal cell. The appendix of the fork of 
the third vein is present upon one wing only. 
19. Petrorossia gratiosa, sp. nov. (Plate L, fig. 14.) 
¢. Length, 5 mm. 
A very small, pretty species, allied to the preceding one, but 
abundantly distinct by the wholly orange-red abdomen and different 
venation. 
Head velvety black, the frons shining in the middle, clothed with 
