1934 ] 
Entomological Investigations in Panama 
177 
pyloric orifice of the stomach while two were found unat- 
tached in the stomach contents. These larvae were large 
and apparently nearly mature. This seems to be the first 
record of this species in Panama and since it was found in 
an animal that had always been on the Isthmus there is no 
doubt regarding it being established in Chiriqui, at least. 
Stomoxys calcitrans Linnaeus. These flies were very com- 
mon in the vicinity of Camp Pital and great numbers of 
them could be found feeding upon the pack mule all during 
the daylight hours. They apparently made no attempts to 
attack man. 
Cochliomyia macellaria Fabricius. The screw worm flies 
were extremely abundant in the vicinity of Camp Pital dur- 
ing our stay there. They usually appeared in large num- 
bers as soon as animals that had been killed were brought 
into camp and they became very active in darting about 
and attempting to deposit their eggs on the carcasses. The 
hunters, after killing and bagging animals, frequently left 
them lying by the side of some forest trail or hanging from 
the branch of a tree to be carried into camp on their re- 
turn. Sometimes these bagged carcasses were left for peri- 
ods of three or four hours and when much bleeding occurred 
the bags become blood soaked and large masses of eggs, 
most of which were probably of C. macellaria , were depos- 
ited on them. Occasionally these masses of eggs were sev- 
eral inches in diameter and nearly half an inch thick, and 
must have represented the ovipositions of large numbers of 
the flies. There were often a number of such masses at- 
tached to a bag, adhering very tightly to the cloth and dif- 
ficult to remove completely by washing or scraping. A 
novel method finally evolved for cleaning the bags was to 
hang them in a stream and let the countless numbers of 
small minnows that were present tear the eggs from the 
cloth and devour them. These minnows came in great num- 
bers as soon as an egg-bearing bag was placed in the water 
and they remained to feed as long as a single egg was avail- 
able. 
Simulium quadrivittatum Loew. The small blood-suck- 
