MARK: BRANCHIOCERIANTHUS URCEOLUS. 191 
In the alcoholic specimens which I have measured the stalk below the 
constriction varies from 105 mm. to 200 mm. in length, and from 3 mm. 
to 5 mm. in diameter. The enlarged bulb-like end is from 6 mm, to 
8 mm., or even more, in diameter. But in preserved specimens the 
stalk is much folded lengthwise, so that the direct measurement of its 
diameter is not reliable. A portion of the stalk of a medium sized indi- 
vidual cut out, slit open lengthwise, and pinned out, measured 22 mm., 
so that the corresponding diameter would be about 7 mm. The bulbous 
enlargement reaches about twice that diameter. The column is smooth, 
except for very minute appendages at the basal end, and marked by 
narrow longitudinal brownish lines about 0.2 mm. broad, alternating 
with lighter colored brownish or buff ones about three times as wide 
(0.6 mm.). The darker lines in the fresh specimen are bright brick-red. 
Individuals differ much in the depth of color, which ‘in all is less in the 
bulbous region, where the distinction between the light and dark lines 
almost disappears. The wall of the stalk, though not very thick, is quite 
rigid ; that of the bulb is somewhat thinner. The bulb terminates in 
a small, nipple-like elevation ; but a terminal pore, if present, must be 
vory minute, for I have been unable to detect one by examination of 
specimens in toto. The bulb often contains a large quantity of the 
shells of Foraminifera. 
The outer surface of the lower part of the bulb is provided with small 
tapering filamentous appendages, which are 50u to 75u in diameter at 
their basos, but diminish abruptly to less than half that diameter and 
then taper gradually to a point. They vary in length from 0.5 mm. to 
1 mm., rarely more in alcoholic material, and are rather evenly distrib- 
uted over the surface at distances of 0:5 or 0.3 mm. apart; but they are 
not arranged in any definite pattern. They remind one of the peculiar 
appendages of the egg shell in Fundulus heteroclitus, especially of those 
of the half grown ovarian eggs (cf. Eigenmann, 790, Plate I. Fig. 6). 
The lower end of the column, its bulbous enlargement, is invested 
by a case which extends upward at least for a tenth of the length of the 
column, and is open at its lower end. It is, of course, the secreted 
product of the lower and of the column, but it has a more complicated 
structure than is common in sheath-inhabiting actinians. In an indi- 
vidual whose stalk was 200 mm. long the case was about 25 mm. long, 
exelusive of the peculiar hair-like appendages which it bears. The 
lower three fifths of the caso differs from the upper two fifths in possess- 
ing very numerous long hair-like hollow appendages. The upper two 
fifths may be divided into two zones of about equal breadth. The secre- 
