158 DIPTERA. 



1. Systropus rogersi, sp. n., <j ? . 



Four front legs yellow ; hind legs black, except the tip of the femora, the extreme root and the tip of the tibiae, 

 and the first joint of tarsi, which are yellow ; antennae black ; abdomen black, slightly hoary on the 

 incisures. 



Length 27-28 millim. 



Hab. Costa Rica, Irazu 6000 to 7000 feet (Rogers). 



Face pale yellow ; frontal triangle yellow ; palpi reddish-yellow ; antennae black, the 

 last joint about one and a half times the length of the preceding one. Thorax black, 

 except the following parts, which are pale yellow : — (1) a large spot above the front 

 coxae ; (2) the sides of the mesonotum in front of the root of the wings and including 

 the humeral callosity ; this spot has the shape of a capital Greek gamma on the left 

 side, and of a gamma reversed on the right ; (3 ) a small spot on the post-alar callosity ; 

 and (4) another spot on each side below the scutellum ; some reddish-yellow also below 

 the root of the wing. In the middle of the mesothorax a geminate, greyish stripe, show- 

 ing hoary reflections. Halteres yellowish-brown ; tip of the knob yellow. Coxae black ; 

 four front legs yellow ; hind legs black, except the end of the femora, the extreme root 

 and tip of the tibiae, and the first joint of the tarsi, which are bright yellow. Abdomen 

 black : the hind margins of segments 2, 3, 4 with small lateral triangles of greyish 

 pollen, the first segment also greyish on the sides. Wings tinged with brownish; 

 venation like that of S. macer. Five specimens. 



2. Systropus cerdo, sp. n., <s . 



Antennae yellow, the third joint black ; legs reddish -yellow, the hind tibiae and tarsi black ; abdomen reddish, 



with a brown line on the upperside of the basal segments. 

 Length about 17 millim. 



Hab. Panama, Volcan de Chiriqui 2000 to 3000 feet (Champion). 



Face, frontal triangle, palpi, and antennae pale reddish-yellow ; third joint of the 

 latter black. Thoracic dorsum shining black, with a microscopic punctuation ; on the 

 left side of the mesonotum a pale yellow spot in the shape of a Greek capital gamma, 

 with a similar spot, only reversed, on the right side ; from this spot a yellow stripe goes 

 down towards the front coxa ; on the pleura there is a large black spot immediately 

 under the dorso-pleural suture, and another one above the middle coxa, both are 

 whitish-sericeous, separated by a yellow stripe ; the interval between the hind coxae 

 and the root of the abdomen pale yellow, with a pair of elongated black spots 

 immediately above the coxae, and another pair of larger, circular spots towards the root 

 of the abdomen. Halteres brownish-yellow ; knob with a brown spot in the middle. 

 Scutellum and first abdominal segment black, whitish sericeous ; the upperside of the 

 three following segments brownish ; the rest of the abdomen as well as the under- 

 side of the basal segments reddish, with a fulvous microscopic pubescence. Legs 



