1910] Girault and Sanders — Chalcidoid Parasites 11 
and mandibles and apparently also by means of sight. (6) The 
deposition of an egg observed at 9:45 P. M., Sept. 14, required 16 
minutes; the host was Phormia regina. Another observation made 
at 10:15 A. M. the same day, showed that the act required 8 minutes; 
the host puparium was that of Musca domestica; in the latter case, the 
ovipositor was inserted into the 9th segment of the host. A female 
was observed to deposit an egg in confinement at 7:30 A. M. to-day. 
(7) A female confined at 9: 20 A. M., Sept. 10, deposited into puparia 
of the Phormia at 9:32 A. M. and 1:20 P. M. the same day. One 
confined at 10 A. M. the same date with 2 puparia of the same host 
oviposited at once. (8.) In the cases of 4 females confined separately 
in vials each with 4 (in one case 8) puparia of Cynomyia cadaverina 
Desy., April 29, 1909, oviposition occurred with one female at 10:25 
P. M., April 30, and again at 9 P. M., May 1; no other observations 
were recorded. (9.) Nine males and twenty females confined at 
11:20A. M., April 29, with 10 puparia of the same host commenced 
oviposition about noon, or sooner, and oviposition was observed at 
nearly every hour between 9 A. M. and 11 P. M., for several days. 
B. Nature of the Parasitism. Examinations made of parasitized 
hosts, showed that in all cases, the parasite is “social” or gregarious 
and does not attack the host until after the formation of the puparium, 
preferably after the latter has been formed for at least twenty-four 
hours. Puparia of Phormia regina examined, were in some cases filled 
entirely with the larvae of the parasite which had totally consumed the 
host pupa; for example, from one puparium 47 larvae of the parasite 
were removed; from another 8 larval parasites were removed, together 
with a shriveled pupa of the host — none of the parasitic grubs had 
entered the body of the latter, which indicates that the parasites are 
external as far as the host pupa is concerned, obtaining their nourish- 
ment by means of absorption; in the case just cited, one of the parasitic 
larvae was attached to the head of the host pupa over the eye, one to 
the thorax and six to the abdomen. In a third Phormia puparium, 
there were found 21 larval parasites, the host pupa being totally con- 
sumed; in four more single cases there were 8, 13, 13 and 16 larvae of 
the parasite respectively. In another, 27 parasitic pupae were found, 
from a single puparium of Sarcophaga sp. “e” 22 o\o and 4 2 2 of 
the parasite were taken. As a rule, the remains of a parasitized host 
— the fully formed pupa — is a flat, scale-like mass apparently con- 
sisting of the ventral shell of the pupa and that of the head; for 

