HOUGH: SOUTH AMERICAN MUSCID.E. 205 



The head of the female is 3.0 mm. wide in one of the speci- 

 mens and 3.1 in the others, the front being in the former 0.8 

 ram. and in the latter 0.9 in width. The vitta is not pollinose. 

 The geno-vertical plates are yellowish gray pollinose on their 

 ventral half or two-thirds, polished on the dorsal half or third. 

 The transfrontal bristles are ten or twelve in number and are 

 rather stout (as are all the bristles of the head). Laterad the 

 transfrontals are two proclinate orbitals in the usual position 

 and ventrad these a number of tiny bristlets. The great ocellar 

 bristles are normal in direction but not large. There are 

 several pairs of lesser ocellars, one of which, situated just 

 caudad the posterior ocelli, is about half as large as the great 

 ocellar, while the postvertical is very small and delicate. Lat- 

 erad the ocelli is one ascending frontal. The inner and outer 

 vertical bristles are of good size ; the occipito-central is present, 

 the occipito-lateral absent. 



The cilia of the posterior orbit form a single normal row in 

 both sexes. The dorso-ventral diameter of the bucca is one- 

 fourth that of the head. 



The cha'totaxy of the thorax is shown in figure 1. There is 

 some variation in the dorso-central bristles. We always find 

 three caudad the transverse suture, as represented in the dia- 

 gram. The most caudad is the largest, and the third is the 

 smallest of these three. Cephalad these we find either one or 

 two more, so small as to be distinguished with some difficulty 

 from the microchset^e. If but one is present, it is larger than 

 either of the two, if two are present. Cephalad the transverse 

 suture there are always two of small size and sometimes a third, 

 which may be midway between the other two or nearer the 

 more cephalad of them. I have indicated in the diagram that 

 there are two small bristles on the disc of the scutellum. In 

 small specimens there may be but one, and in large specimens 

 one of the two may be marginal. 



In the Sarcophagime, Calliphorime, Muscinie, and Crenosiina^, 

 the bristles of the scutellum are as follows : (1) Jugal, a small 

 bristle inserted on the caudal end of the little jugum, which 

 unites the scutellum near its cephalo-lateral angle with the 

 mesonotum ; (2) postjugal, the large bristle just caudad the 

 jugal, inserted on or very near the margin of the scutellum ; 

 (3) apical, the large bristle inserted very near the apex of the 



