1935] Larva and Puparium of Physocephala sagittaria 145 
cephalic margin and extending cephalad below each oral 
hook is an elongate sclerite (t). This sclerite probably 
aids in supporting the walls of the pharynx. The cephalic 
end of the pharyngeal sclerite extends cephalad to form a 
weakly sclerotized, curved bar which aids in strengthen- 
ing the roof of the pharynx. 
The anterior spiracles are absent but the posterior ones 
are well developed and conspicuous. These are two kidney- 
shaped plates on the last segment (fig. 4, sp). They are 
strongly convex and vary in color from a reddish-brown to 
a dark brown depending upon the age of the larva. The 
stigmal plates bear numerous wart-like protuberances (fig. 
6) and on each plate there is, approximately centrally 
placed, a round pale spot. Surrounding these convex plates 
at the base is a narrow rim or collar-like structure (fig. 4, 
u). In most specimens this collar is slightly darker than 
the remainder of the plate. Each stigmal plate is slightly 
emarginate in the mid region of its mesal border. The 
surrounding rim is widest at this emargination. Slightly 
beyond the dorso-lateral margin of each stigmal plate there 
is a small spine (fig. 6, v). This structure appears to be 
sclerotized and is the color of the stigmal plate. The wart- 
like protuberances of the stigmal plates seem especially 
significant and these with the general shape of the larva 
should enable it to be recognized as a conopid. The anus 
lies immediately ventrad of the stigmal plates. 
Puparium. — The puparium (fig. 1) is formed within 
the abdomen of the host and is approximately 8 mm. in 
length and 5 mm. in breadth. It is reddish or dark brown 
in color. The individual segments are very poorly indi- 
cated and the surface is smooth. The stigmal plates (figs. 
1, 5) retain their characteristic appearance but project 
outward more than in the larval stage. They are slightly 
smaller and the shape is not exactly as it was during the 
preceding stage. Figures 5 and 6 illustrate this difference 
in size and shape. Each stigmal plate appears as though 
a string had been tied around its base and the string 
tightened thus causing the plate to become more convex 
and to bulge. The wart-like protuberances are even more 
prominent than in the larval stage. 
