604 
Fig. 
The American Naturalist. [July, 
B.—Later stage of A, showing growth of septum and 
consequent introversion of edge of lophophore. Cis- 
telliform stage. 
. B1.— Cistella neapolitana Scacchi, showing calcification of 
loop attached to septum, and other adult features. 
Morphic equivalent of stage B of Magellania. 
. C.—Third stage of Magellania, with small ring on sep- 
tum. Bouchardiform stage. 
. Ca.—8Side view of same. 
. C1.— Bouchardia rosea Mawe, adult, showing ring on sep- 
tum as in C. 
D. — Megerliniform stage of Magellania. 
. Da.—Side view, showing growth of descending branches 
as prongs on side of septum. 
. D1.—AMegerlina lamarckiana Davidson, adult form of 
brachial supports. 
. E.—Magadiform stage of Magellania, showing completion 
of descending branches. 
. El.—Magas pumilus Sowerby, the Cretaceous prototype of 
this structure. 
. F. —Magaselliform stage, showing union of descending 
and ascending branches. 
. F1.— Magasella cumingii Davidson. 
. G. — Terabratelliform stage, representing the finished type 
of structure in Terebratella dorsata. 
. G1.— Terebratella rubicunda. Morphically equivalent to 
G, but showing more mature features. 
. H.—Final stage of Magellania venosa, produced by resorp- 
tion of the septum and connecting bands of the tere- 
bratelliform stage. 
Fig. Hi .— Magellania flavescens Lamarck. 
