229 THE BLOWFLIES oF NortH AMERICA 
Bufoluciha silvarum has been reared from frogs in North _ 
America in only one instance so far as I know; Mr. W. B. Cart- 
wright, of the Bureau of Entomology and Plant Quarantine, 
kindly furnished me with the following record. In November, 
frogs (Rana catesbeiana, eastern bullfrog introduced into Cali- 
fornia) were found on the moist banks of a slough of the Moke- 
lumne River, south of Franklin, California, infested with 
maggots of this species. Of 59 frogs examined, 22 had appar- 
ently been killed by these larvae, 11 living frogs had both eyes 
infested, and 15 living frogs had one eye infested. The larvae 
were milling around in a mass in the orbits of the eyes but 
had not penetrated the eye balls. Some larvae were observed to 
migrate from one eye to the other. Thirty-two larvae were found 
in an eye of one frog. Those reared emerged as adults late in 
February or early in March. 
Larva. First instar: Spines distinct, heavily pigmented; 
complete band of spines at anterior border of segments 1 to 9; 
segment 10 usually without spines dorsally; posterior border of 
segments 9-12 completely encircled with spines; segment 9 with 
band narrowed to one or two dorsal rows; spines restricted to 
lateral and ventral surface on segment 8; border of stigmal 
field provided with long brownish hairlike spines. Tubercles of 
last segment as in illustris. Cephaloskeleton (pl. 39, A) with 
parts rather well-developed, the principal distinguishing feature 
being the broad pharyngeal arch, which is much broader than 
in other species. 
Second instar: Segments 2 to 9 each provided with a complete 
band at anterior border, spines present on lateral surface of seg- 
ment 10, but absent on dorsal surface; posterior border of 
segments 9-12 with a complete band, narrowed to one or two 
irregular dorsal rows on segment 9. Relative position of tubercles 
on stigmal field as in third instar, broad at base and somewhat 
pointed at tip. Pharyngeal sclerite (pl. 39, B) rather lightly 
pigmented, labial sclerites rather narrow and the dorsal posterior 
prolongation of basal portion narrower than in all other species 
except pallescens; shape of dorsal cornua about intermediate 
between that of allustris and caeruleiviridis. Anterior spiracles 
with five to seven branches, more often with six. 
Third instar: Spines encircling body at anterior border of 
segments 2-9; on segment 10 several rows of spines extending 
almost to dorsal surface, and on segment 11 two or three irregu- 
lar broken rows of spines present laterally; posterior border of 
segments 9-12 with complete band of spines; segment 11 with 
six to eight irregular rows dorsally, segments 9 and 10 with 
