SUBFAMILY CALLIPHORINAE 287 
illustrated, hypostomal sclerite posteriorly prolonged, parastomal 
sclerite long and narrow, pharyngeal sclerite pigmented medi- 
anly and toward dorsopharyngeal sclerite. 
Third instar: Mainly as in previous. instar. Cephaloskeleton 
(pl. 42, B) with length and breadth of labial sclerite in propor- 
tion 1.5:2, cornua lightly pigmented dorsally and ventrally. 
Posterior spiracles separated by a distance nearly equal to the 
diameter of one spiracle, each (pl. 42, D) with three slitlike 
apertures, the outer slits being nearly in a horizontal plane, the 
‘“button’’ in peritreme, large, both ‘‘button’’ and peritreme well 
pigmented. 
The larvae complete feeding in 4 or 5 days during midsummer 
and form puparia 8 to 12 days later. The total larval period is 
usually about 13 days although a few larvae may postpone form- 
ing puparia for as long as 25 to 30 days. 
Adult. Both male and female specimens may be collected upon 
excrement of carnivorous animals or upon decaying substances, 
particularly meat. Many specimens may be seen about entrances 
to gopher burrows but the reason for this habit has not been as- 
certained. This species is one of the most abundant blowflies in 
the Rocky Mountain section of the United States where it appears 
early in the spring and remains until late in September. 
It has been noted by Townsend (1937, p. 148-149) that females 
of this species with partially extruded larvae often occur in col- 
lections, and that this indicates a double-sae uterus of the Onesia 
type. The uterus of lilaea is similar in most respects to that of 
Calliphora. 
Hough (1899) erroneously referred Musca lilaea Walker to 
Calliphora erythrocephala (Meigen). He did not see the Walker 
type. 
Eucalliphora arta, new species - 
Differs from lilaea only in the following characters : 
Male. Head height 8.4; eye height 6.3; bucca 0.33 eye height; 
length at antenna 5.0 and at vibrissa 5.1; parafaciale 1.2 in 
width opposite lunule; vibrissae set 2.4 apart; front at narrowest 
0.18 head width, 0.23 at vertex and 0.31 at lunule. Legs with 
femora obviously less bristly; middle tibia with two posterodorsal 
bristles. Wing with costal sections 2 to 6 in the proportions 
60 :32 :85 :42:6. Posterior view of forceps of genitalia (pl. 27, C) 
as illustrated. 
Female. Head height 8.8; eye height 6.0; bueca 0.48 eye 
height; length at antenna 5.3 and at vibrissa 5.9; parafaciale 1.5 
in width opposite lunule; vibrissae set 2.5 apart; front at vertex 
