218 Mr. F. Walker's Characters of undescrihed Diptera 



black ; abdomen witb the white slightly gilded, with a black 

 stripe, and with a black band on the fore border of each segment ; 

 wings limpid ; veins testaceous, black towards the tips ; discal 

 transverse vein slightly curved inward, parted by more than half 

 its length from the border, and by less than its length from the 

 praebrachial transverse vein ; alulse white. 



Length of the body 2h lines ; of the wings 5 lines. 



Port Natal. 



Div. 2. ACALYPTER^. 



Sub-fam. 1. Helomyzides. 



Tlie exotic genera are here enumerated, with the characters 

 which chiefly distinguish them from the most nearly allied Euro- 

 pean genera, and the same plan is used with respect to some of 

 the following sub-families : — 



1. Thecomyia, Veriy ', facies elongata. 

 Tetanocera, Dum. ; facies non elongata. 



2. Curtonotum, Macq. ; thorax gibbosus. 

 Helomyza, Fall.; thorax non gibbosus. 



3. Pyryota, Wied. ; abdomen apice clavatum. 

 Otitis, Latr. ; abdomen depressum. 



4. Dichroniyia, Desv. ; pedes nudi. 

 Actora, Meig. ; pedes villosi. 



5. Ectecephala, Macq. ; antennae elongatae. 

 Eurina, Meig. ; antennae non elongatas. 



6. Orthostylum, Macq. ; arista recta. 

 Cordylura, Fall. ; arista non recta. 



7. Chcetura, Macq. ; tibiae posticae arcuatae. 

 Cordylura^ Fall. ; tibiae posticae non arcuatae. 



Genus Scatophaga, Meig. 



Scatophaga canadensis. 



Fcein. — Cervina, capite fulvo, subtus pallido subaurato, antennis 

 fulvis, arista nigra subtomentosa, thorace vittis tribus fuscis, 

 nietathorace cano, abdomine cinereo apice fulvo, pedibus 

 fulvis, alislurido-subcinereisjVenistransversisnigro-nebulosis. 



Female. — Fawn colour ; head tawny in front, pale and with 

 slightly gilded tomentum beneath ; anteunaj tawny ; arista black, 



I 



