ART. 15 NOTES ON ACALYPTRATE FLIES — MALLOCH 13 



KEY TO THE SUBGENERA 



1. Fuce with erect sparse microscopic hairs; occiput with a bristle behind post- 



ocular orbits a little above middle of eye ; sides of postnotum above bases of 

 halteres usually with fine but distinct erect hairs; no spiracle-like openings 

 on the dorsal exposure of third and fourth visible terf,'ites. 



Plagiostenopterina Heudel, genotype aenea Wied. 



Face entirely without hairs; postnotum without distinguishable hairs on 



sides 2. 



2. Third and fourth visible tergites in female each with a pair of spiracle-like 



openings on dorsal exposure ; anterior margin of thoracic dorsum with four 

 bristles ; mesopleural bristle present. 



Stenopterella, genotype trivittata Walker. 

 Third and fourth visible tergites without spiracle-like openings 3. 



3. Humeral and occipital bristles present; mesopleural bristle well developed. 



Elassogaster Bigot, genotype, metallicus Bigot. 

 Humeral and occipital bristles lacking 4. 



4. Mesopleural bristle present Bakeromyia, genotype, calcarata Macquart. 



Mesopleural bristle lacking Carolimyia, genotype, diptera, new species. 



Subgenus Plagiostenopterina Hendel 



The haired face, almost invariable presence of humeral and meso- 

 pleural bristles, and of hairs or pile on the basal section of the third 

 wing vein, distinguish this subgenus from the others, but only the 

 first-mentioned character is possessed by this group exclusively, one 

 or more of the other characters recurring in the others. 



Many of the species placed in Plagiostenopterina by Hendel are 

 unknown to me, but I present below a key to those now before me 

 in the hope that it may be useful to students of the family. 



KEY TO THE SPECIES 



1. Tarsal claws of the male with a very pronounced basal lobe, those of the 



female with a distinct basal angle ; wings blackened, the costal, and central 

 basal black stripes hardly darker than the remainder of the field. 



samoaensis Malloch. 

 Tarsal claws in neither sex with either a basal lobe or distinct basal angle ; 

 wings hyaline, basal half of center of wing, and costa each with a con- 

 spicuous dark stripe 2. 



2. Scutellum, smooth, dusted, without punctures or short fine hairs on disk; 



humeral angles rather densely furnished with black hairs, the usual bristle 



very poorly or not at all differentiated parva, new species. 



Scutellum either granulose or with closely placed piliferous punctures, the 

 hairs generally pale and fine and most readily seen when the surface Is 

 viewed from behind; humeral bristle always well developed 3. 



3. Mesopleural bristle lacking ; hairs on aristae about three times as long as its 



basal diameter at base of third segment; mesonotum without trace of a 

 central white dusted vitta ; frons entirely dull, nowhere distinctly shining; 

 section of costa between apices of first and second veins subequal to that 

 between second and third ; second visible abdominal tergite of female 

 violet-black, densely brownish black haired on posterior lateral regions of 

 dorsal exposure, and distinctly different in color from the other tergites 

 which are metallic blackish blue; hind tarsi pale haired above; male 

 without an apical palette formosae Hendel. 



