in the Collection of W. W. Saunders, Esq. 157 



Genus Syrphus, Fabr. 

 Syrphus subchalyheus. 



Fulvus, capite antico glauco, thorace vittis duabus seneis Hneis- 



que duabus intermidiis fulvis, tibiis posticis piceis, alis cine- 



reis, dimidio basali antice lurido. 



Tawny ; head glauceous in front ; thorax with two eeneous 



stripes, each of which is intersected by two tawny lines ; hind 



tibiae piceous ; wings grey ; basal half, excepting the hind border, 



lurid ; veins ferruginous. 



Length of the body 5 lines ; of the wings 10 lines. 

 Valley of the Amazon. 



Genus Rhoga, n. g. 



Mas. — Parago aflRnis, caput sat angustum, oculi supra non con- 

 nexi ; antennarum articulus 1"^ longus ; 3"^ brevior, sub- 

 clavatus ; arista nuda ; abdomen sessile oblanceolatum, 

 thorace vix duplo longius ; tibiae posticae subdilatatae, sub- 

 ciliatse ; metatarsi postici dilatati. 

 Male. — Body rather narrow ; eyes parted above ; first joint of 

 the antennae much longer than the third, which is subclavate ; 

 arista bare ; abdomen sessile, oblanceolate, hardly twice the length 

 of the thorax ; hind tibiae slightly dilated and ciliated ; hind me- 

 tatarsus dilated ; wings with the veins much like those of Paragus 

 in structure ; transverse praebrachial vein placed much before the 

 middle of the discal areolet ; transverse praebrachial vein rejecting 

 a branch towards the base of the wing. 



Rhoga lutescens. 



Mas. — Pallida lutea, thoracis disco nigro, tibiis posticis extus 

 nigro-pilosis, alis limpidis, fascia apiceque subcinereis. 



Male. — Pale luteous ; head with a black callus on the vertex, 

 and another above the base of the antennae ; thorax with a large 

 black radiating spot on the disk ; hind tibiae with black hairs on 

 the outer side ; wings limpid, greyish in the middle and at the 

 tips ; veins pale luteous, black in the grey part ; halteres tes- 

 taceous. 



Length of the body Sg lines ; of the wings 5 lines. 



Para. 



