BY FREDERICK A. A. SKUSE, 
1371 
coast of Australia by M. Verreaux (Dipt. Exot. 4tli Suppl. 
1850, p. 18), but I have not yet discovered specimens. 
The descriptions of (177) B. clavatits, Macq. ; (178) B. nigri- 
tliorax, Macq. ; (179) B. serricornis, Macq. ; (180) B. rufiventris, 
Macq.; (181) B. ruhiventris, Macq.; and (182) B. elegans, Jsennicke, 
recorded from Australia in Walkei’’s “Notes on Diptera (1874),” 
are at present inaccessible to me. It would not surprise me if 
most of these eventually prove synonymous with B. imitator. 
I have specimens of the latter which might well be called davatus, 
nigrithorax, rujiventris or ruhriventris. If in killing, the 9 
left too long in the chloroform bottle, all the bright colouring 
disappears, and the abdomen assumes a black appearance. 
Genus 2. Plecia, Wied. 
Plecia, Wiedemann, Auss. Zw. I. 1828, p. 72 ; Macquart, S. a 
B. Dipt. I. 1834, p. 175, etc. 
“ Hea.d small, hemispherical, not so wide as the thorax in the 9 . 
Probo.scis projecting, thick. Labrum rather large, pointed. Palpi 
five-jointed ; first joint small ; third large, conical. Face as long 
as the front, convex, projecting to the upper part. Front rather 
wide, carinated in the 9. Antennte perfoliated, inserted a little 
lower than the middle of the eyes, 11 -jointed ; the first two joints 
short, cylindrical, little separated from one another ; third rather 
large, cyathiform, a little elongate ; the following joints short, a 
little rounded, diminishing somewhat in .size ; the last very small. 
Eyes convex, rounded. Thorax with two indented lines. Legs 
nearly naked ; fore-legs : femora elongated, dilated at the apex ; 
tibiie elongated ; first joint of the tarsi a little elongated ; the 
rest rather short. Wings once longer than the abdomen in the 
9 ; two basal cells ; two marginal 9 ; second posterior cell 
petiolated.” 
Obs. — I must remark here that the above number of antennal 
joints cannot bo taken as a genei ic character, as in the appended 
de.scrij»tions it will be seen that although B. amp/ipomis 9> 
