78 Psyche [April 



2. Face translucent yellow; thorax weakly bivittate. S. Am., Mex.* {nrina 



Giglio-Tos) ferruginea Schiner. 



Face trimaculate; thorax quadrivittate. W. Ind.*, S. Am.; Vera Cruz, Aldrich 

 {obscuripetmis Bigot, variegata Loew, nasalis Thomson) (fig. 6) 

 vittata Macquart. 



This genus is easily recognized by the greatly swollen and trans- 

 lucent face. The species are reddish yellow in color. The brief 

 description of Lauxania 'planiscuta by Thomson brings to mind the 

 other species of Physogenia: the testaceous color, the convex 

 protuberant glabrous face, the position of the anterior cross vein 

 much beyond the end of the first vein and the vittate thorax are 

 rather distinctive characters. Possibly it is a synonym of fer- 

 ruginea. Lauxania nasalis Thomson is certainly the same as 

 vittata Fabricius. The erect dark stripe of the pleura, surmounted 

 by a velvety black spot, the black dots above the antennae, and 

 the greatly swollen face indicate the synonymy. 



Genus Pachycerina Macquart. 



The North American species previously assigned to Pachycerina 

 are to be found in Camptoprosopella. The present species differs 

 from the type of Pachycerina, the European seticornis Fallen, in the 

 following structural characters which hardly have generic value: 

 The occiput is flattened instead of convex, the face is gently convex 

 instead of bulbous, the anterior fronto-orbital bristles are more 

 strongly inclinate, the third antennal joint is elongate-linear 

 and the short arista is loosely plumose, instead of the antennae 

 tapering and arista with appressed pubescence. There are three 

 dorsocentral bristles, six distinct rows of acrostichals, one humeral, 

 one presutural, two notopleural, one supraalar, two postalar, one 

 pair prescutellar, four scutellar, the apical pair parallel, one meso- 

 pleural, one sternopleural and one prothoracic, all but the last two 

 directed backwards, the sternopleural and prothoracic bristles 

 directed upwards. Seticornis has four dorsocentrals and two rows 

 of acrostichals, but the other bristles are arranged as in the follow- 

 ing species. 



From Camjjtoprosopella the present species differs in the convex 

 face and narrower facial orbits. In Camptoprosopella the sides of 

 the face are broad and join the oral margin so that the central 

 portion of the face takes no part in the formation of the cheeks. 



