DIPTERA 55 



Drosophila Fallen. 



This genus is represented by nearly hity species, of which forty are here dealt with. 

 I cannot satisfactorily refer any of these to already described forms, and therefore have 

 regarded them all as new. Owing to the absence of any striking characters in some of 

 the smaller species I have found it impossible, without reference to types, to decide 

 whether they may or may not belong to certain previously-described North American 

 or European species, with the descriptions of which they agree in many particulars. 

 I hardly think it likely that the native species will be found elsewhere, so that the 

 chances of the names given below being reduced to synonyms will only apply to one 

 or two which may (though this is an unlikely supposition) have been introduced. I have 

 left eight specimens undetermined, owing to their bad condition. 



Key to specks. 



1 . Wings with a dark pattern or witli dark spots 2. 



„ not so marked 1 1 • 



2. Tiliiae pale yellow, conspicuously banded with dark brown (/) D. picticornis. 



,, not banded 3- 



3. Thorax light yellow, with a single broad central stripe and three conspicuous 



lateral spots blackish {2) D. variega/a. 



Thorax not so coloured 4- 



4. Wings with costal and apical borders continuously infuscated 5- 



,, without continuous fuscous border 6. 



5. Fourth longitudinal vein distinctly curved near its apex (j) D. undulata. 



straight {^4) D. pcrkinsi. 



6. Thorax yellow, with four conspicuous black stripes ; scutellum yellow with 



broad central dark stripe is) D. conspicua. 



Thorax unstriped or with less than four stripes ; if four inconspicuous 



stripes are present the scutellum is entirely yellow 7. 



7. Third longitudinal vein with a fuscous spot opposite the posterior trans- 



verse vein 8- 



Third longitudinal vein without such spot 9- 



8. Infuscation in marginal cell or on middle portion of second longitudmal 



vein extending to a distance equalling the whole breadth of the wing. ..((5) D. lanaieitsis. 

 Infuscation in marginal cell or on middle portion of second longitudinal 

 vein only about as broad as the length of the posterior transverse vein 



(-) D. haivaiicnsis. 



9. A fuscous spot on the middle of the second longitudinal vein 10. 



No „ „ „ „ {10) D.paucipunda. 



10. Pleurae entirely yellow {S) D. ochraaa. 



„ marked with dark brown {9) D. pilimana. 



11. Ape.x of wings more or less infuscated •-• 



„ „ clear i?- 



12. Base of fore femora furnished on the inner side with a brush of short, stiff 



black hairs {n) D. aiiomalipes. 



Fore femora unarmed ' 3- 



