268 
At the time of fixation the pupa is rather siender (Fig. 27 a) 
with stout and strong prehensile antennae; the animal is now dark 
brownish pigmented, with a lighter area in the eye region. Very 
soon a curious metamorphosis of the pupa is observed: the animal 
(Fig. 27 b) attains a quite different shape with a straight occludent 
margin, a spine at the posterior (upper) end of each pupa-valve, 
b 
Fig. 26. 
b 
Fig. 27. 
Figs. 26 and 27. Lepas pectinata from 36° 00’ S., 150° 20’ E. 
Fig. 26. a mandible, b maxilla. [X 44]. — Fig. 27. a pupa just attached; b older 
pupa about to develop the primordial valves; c the same in the dorsal aspect. [X22]. 
and a highly arched dorsal line. Round the prehensile antennae 
the pupa-cover bulges out so that the antennae are invisible in side 
view. In dorsal aspect the pupa is now broad, and the bulgings 
at the antennae are seen as well-defined, almost mamillate pro- 
minences standing out from the sides of the animal near its ante- 
rior end. The curious dorsal double row of cellular formations 
inside the pupa cover, only seen in the large pupa, probably is 
in some connection with the coming moulting. Unfortunately the 
material could not solve the question as to the deeper meaning of 
these structures; it shall be an interesting task for a student at a 
biological station of the Tropical seas to solve the physiological 
questions concerning the floating barnacles, and especially their 
metamorphoses. 
Within the singular, large pupa described the last metamor- 
/ 
