4 



dae and the genus and species of Tanyderidae (Bruchomyia argentina) 

 is now placed in the Psychodidae (subfamily Phlebotomyinae). 



Another family, Psilidae, of which Weyenberg described a species, 

 Chiliza persicorum, from Argentina, is omitted from Bréthes catalo- 

 gue. After these additions and changes have been made, we find that 

 there is a total of fifty-one families recorded from Argentina. 



At least twenty-two other families are known to occur in other 

 regions of America, the majority of which, no doubt, will be found in 

 Argentina. It must be stated, however, that sinee the work of Félix 

 and Enrique Lynch Arribalzaga, very little comprehensivo work has 

 been done on the Díptera of Argentina, with the exception of that on 

 the Culicidae, Tabanidae, and the gall-making Itonididae (Cecidom- 

 yidae) and Trypetidae. There f ore, it is natural to expect that niany 

 new forms await discovery. This is very evidently the case, as is shown 

 by the fact, that the writer, with limited time at his disposal for gene ral 

 collecting, has obtained representatives of eight of these unrecorded 

 families, namely : 



Leptidae (Tucumán) 



Scenopinidae (Tucumán and Buenos Aires) 



Platypezidae (Tucumán) 



Pipunuculidae (Tucumán) 



Tanypezidae (Tucumán) 



Rhopalomeridae (Chaco; also specimens seen in Jujuy) 



Heteroneuridae (Chaco) 



Geomyzidae ( Tucumán ) . 



Dr. Carlos Bruch has collected a species of Pyrgotidae from Cór- 

 doba. 



The Museo de Historia Natural de Buenos Aires contains a spoci- 

 men of the family Apioceridae. In addition to the above, the Than- 

 malidae & Canthjdoscelidae have been found in Patagonia. AU com- 

 bined makes a total of sixty-three families. 



The representatives of the Leptidae, Platypezidae, Pipunculidae 

 and Tanypezidae are described in the present paper; while the others 

 will be treated in a future paper. 



No doubt other species will be found which belong to these fami- 

 lies. Likewise, in the course of extensive collecting many additional 

 genera and species will surely be added to the known fauna of Díptera 

 of Argentina. In fact, it would appear that the number of unknown 

 species far exceeds that which is already known. 



One group of Díptera which is eommon in the Northern Hemis- 

 phere, namely the Scatophaginae, seemingly has no representatives in 

 Argentina. Scatophnga diadema Wiedemann, as stated above, belongs 

 to the family Phycodromidae. Choetura rufipes Macquart, described 

 from Uruguay, and which is likewise recorded under the Scatophagidae 

 (vide Bréthes) is unknown to the writer and cannot be stated at 

 present whether it belongs to the Scatophaginae or not. Occasionally, 

 special • search has been made for this group by the writer without 

 resulta. 



