HOUGH: SOUTH AMERICAN MUSCID^. 219 



middle thirds ; on the posterior surface four, about equidistant, 

 and much smaller than the one on the flexor surface. The hind 

 tibia has on the lateral surface near the flexor border four rather 

 slender bristles ; on same sa^-face near the extensor border there 

 is a complete row from base to apex of unequal but almost 

 equidistant bristles, most of which are small, but about four 

 are of good size ; on the mesal surface near the flexor border 

 there are no bristles; near the extensor border there two, one 

 at the middle and the other at the junction of the middle and 

 apical thirds. 



Graphomyia maculata Scop. 



Two males and two females ; Desteno, December ; Chapada ; 

 Piedra B., April; Corumba, Ma3^ 



The specimens are precisely like those found in the United 

 States. I consider G. americana R. D., G. americana Schin. 

 and very likely also Mvxca sfipata Walk, as synonyms, 



Musca domestica L. 



One male ; Rio de Janeiro ; July. 



MUSCINiE ARICI.EFORMES. 



MUSCINA. 



The separation into genera of the group Muscinii ariciseformes is 

 by no means satisfactory exen to-day. Myospila, Muscina, Clin- 

 opera, Ariria, Spilogasler and Linmophora are all of doubtful extent 

 and perhaps insusceptible of precise definition. Before this prob- 

 lem can be satisfactorily solved a much wider knowledge must be 

 obtained than is at present in our possession. Of the four spe- 

 cies in the collection before me which I think best to refer to 

 Muscina, one has sparsely hairy eyes and sterno-pleurals 2 : 2, so 

 that it might as well be referred to Myospila as to Muscina, but 

 the hairiness of the eyes is so sparse and slight as to be very 

 easily overlooked, in fact, has been overlooked, I think, by pre- 

 vious writers, and therefore I retain it in Muscina; another 

 species agrees in almost every particular with Clinopera; and for 

 a third a new genus might be erected, on account of the form 

 of the wing. 



