SuBrAMILY CHRYSOMYINAE 167 
tubercles, outer and median largest, inner tubercles situated 
ventrally and out of line with median and outer, which are 
closest together. Anal protuberance large, the tubercles widely 
separated; below and between tubercles with spinose areas. Ceph- 
aloskeleton (pl. 37, C) with labial sclerite stout, heavily sclero- 
tized, strongly decurved; hypostomal sclerite short, irregular; 
pharyngeal sclerite with a pigmented process on anterodorsal 
angle, another less obvious at posteroventral angle; ventral longi- 
tudinal grooves apparent. 
The total larval stage ranges from 4 to 15 days, according te 
Bishopp (1917). 
The larvae of regina are normally saprophagous and may be 
found in great numbers in careasses of animals. They also occur 
in abundance in the paunch contents of slaughtered cattle, es- 
pecially if some blood is mixed with these. On the open range, 
especially during the fall and winter, carcasses of large animals 
are responsible for the development of the vast majority of these 
flies. Paine (1912) found the larvae breeding in great numbers 
in the city garbage in Massachusetts, as did Walton in New 
Mexico (1915). 
In eases of myiasis the larvae of regina sometimes cause a 
bloody discharge, which seems to indicate that a certain amount 
of destruction of tissue may take place. In such instances the 
wounds sometimes superfically resemble those produced by Cal- 
litroga americana. 
Puparitum. Length 9.0-9.5 mm., diameter 3-4 mm.; color 
light brown to almost black. The anterior extremity narrowly 
rounded and somewhat constricted subapically; each segment 
with a double transverse band of sclerotized points; posterior 
extremity contracted subapically and easily recognized by the 
submedian spiracles located in a somewhat ill-defined depres- 
sion margined with irregular short, broad, sclerotized tubercles. 
According to Bishopp (1915, p. 323), the pupal stage is 3 to 
13 days in duration in the vicinity of Dallas, Texas. The total 
developmental period covers 10 to 25 days. 
Adult. The adults of regina may be found during the en- 
tire year but are most abundant during the spring and fall 
months. 
This species is typically a cold-weather blowfly, occurring 
most abundantly during early spring months. Carcasses found 
in nature during the winter season in southern United States, 
where the species breeds during much of the entire year, literally 
swarm with maggots of regina. The species becomes less abun- 
dant with the approach of hot weather, and it constitutes only 
