HOUGH: SOUTH AMERICAN MUSCID.E. 215 



smaller and more delicate, and only one or two of them reaching 

 the dignity of macrochaetse. On the mesal surface near the 

 Hexor border there is a series of long hairs, corresponding to the 

 row of bristles on the lateral surface near the fiexor border ; 

 this row is not present in the female. In both sexes, near the 

 extensor border of the mesal surface is a row of from three to 

 five long, strong bristles w^hich are rather longer in the male. 

 The bristles of the hind tibia of .1/. n'olacca Fabr. have a very 

 similar arrangement, but are less numerous and more delicate ; 

 moreover, tliose near tlie Hexor borders are limited to the apical 

 third instead of extending over the apical half or more, and the 

 extensor row of the lateral surface of the male is by no means 

 so well marked and complete. 



The abdomen is of the same color as the thorax. It has 

 no macrocluetci' except on the fourth segment and at the extreme 

 lateral borders of the first and second. The color of the 

 squamuhr varies. The squamula tlioracalis may be opaque, 

 black, dark brown with a yellowish brow^n border, or light brown 

 with still lighter border ; the squamula alaris may have a black 

 border and a center which is hyaline with a blackish tinge, or it 

 may have no border at all and be almost hyaline with more or 

 less of a yellow-brown tinge. The halteres are yellow or yel- 

 lowish brown. 



The wing is shown in figure 4. The third vein is spinose its 

 entire length, the spines being stouter and closer together basad 

 the small cross-vein. In neither male can I see any spines 

 apicad the small cross-vein, which may be due to their having 

 been broken off or being much appressed, or may be a difference 

 between the sexes. 



Length, 6 to 7 mm, 



Morellia violacea Fabr. 



Musca violacea Fabr., Wied. 



C ff rtoneura violacea Fabr., Brauer and Bergenstamin. 



Pijrellia violacea Fabr., van der Wulp. 



Pyrellia maculijjennata Macq. 



Cy rtoneura niaculipehnata Macq., Townsend's Catalogne. 



Pyrellia maculipennin Macq. 



Pyrellia spccialis Walk. 



Pyrellia centralis Lw. 



Four males and four females; Rio de Janeiro, July and 

 August; Rio, November, no date. 



In an article on "Some Muscina^ of North America,'' Bio- 



