74 
Psyche 
[June 
forms a funnel around its posterior end (see Beard, 1942). 
With Euphasiopteryx, the funnel walls are extended by 
a brownish, transparent, acellular membrane, so that the 
larva is completely enclosed in a sac-like structure (figs. 11 
and 12). This type of funnel has been described for certain 
other tachinids, and Nielsen (1909) claims that the saccular 
portion is composed of the compacted walls of host fat body 
cells destroyed by the larva. Pantel (1910) presumed that 
the enclosed larva fed on the host’s body fiuids absorbed 
through the sac walls. However this may be, he stated that 
at a later stage such larvae pierce the sheath and feed 
actively on fat body and other tissues. This may be the 
case with Euphasiopteryx , for most over 6 or 8 mm long 
had ruptured their sheaths (fig. 11). 
In the cone-heads examined, all the darkened external 
funnel openings were situated either in the soft pleural 
integument or in the ventral intersegmental membranes, 
from the first through the eighth abdominal segments (fig. 
11). Internally the basal 1 or 2 mm of the funnel bear 
heavily sclerotized annular thickenings (fig. 12), while 
the whole structure is often enveloped in the lobular fat 
body, covered with blood cells and detritus, and wound 
round with malpighian tubules. The first instar exuviae 
(figs. 11 and 12, Ex) are embedded in the thickened layers 
of cuticle at the funnel base, but no trace of later molts 
has been found. Cast larval skins of the squash bug 
parasite, Trichopoda pennipes Fabr., have been found either 
embedded in the sheath or, more commonly, between the 
maggot and its sheath (Beard, 1942). 
Although the remarkable first instar larvae of Phasiop- 
teryx montana Tns. [E. ochracea (Bigot)] and P. hilimeki 
BB. [E. hilimekii (BB.)] were described and figured by 
Townsend (1912, 1942), drawings of this stage of brevi- 
cornis are included here for comparison. This active, 
armored larva (figs. 1 and 2), shortly after entering the 
host, measures about 0.8 x 0.15 mm. It has already done 
sufficient feeding so that the nine dorsal plates and the 
flanking rows of eight dorsolateral and seven ventrolateral 
plates no longer overlap as shown by Townsend. The light 
brown plates are sculptured, and bear a pattern of round, 
