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of the basis is white, that of the compartments reddish, with longitudinal stripes, some of which 
are darker, others lighter than the rest of the surface. The narrow radii have very oblique 
summits, and are of a dirty white colour, the alae are broader, are of a darker colour and 
have their summits rounded. The sheath is as a rule of a dark purple. The smaller specimens 
are of a conical shape, and are mostly coloured more vividly than the longer: rose-red, with 
somewhat darker longitudinal stripes. The orifice, in the cylindrical specimens especially, is 
very large and distinctly toothed; the upper extremities of the compartments are — especially 
in the larger specimens — slightly curved inwards. 
Size of the specimens: the largest specimen is 4.8 cm. high, half of which height 
is for the cupformed basis, the greatest diameter near the orifice is 2 cm. and that of the 
basis, near the lower extremity 13 mm. The specimens are crowded together and attached to 
pieces of calcareous stone. 
III. Stat. 273. December 23/26, 1899. Anchorage of Pulu Jedan, East coast of Aru-islands 
(Pearl-banks). Depth 13 m. Bottom: sand and shells. 
A single complete and larger specimen, attached to the shell of an oyster. Half-a- 
dozen smaller specimens, which are incomplete, being without opercular valves, are attached 
to the same shell. 
The shape of the shell is cylindrical rather than conical, upper extremities of the rostrum, 
the lateralia, and the carina, slightly curved inwards. Orifice large, pentagonal, toothed. Colour 
greyish white, here and there yellowish, with slightly darker longitudinal lines on the main parts 
of the compartments. Radii have very oblique summits, are broadest at a little distance from 
the orifice, and grow narrower towards the basis. The alae are broader than thé radii, and 
have their summits rounded. 
Size of the specimen: the greatest height is 18 mm., the greatest diameter at the upper 
extremity 16 mm. The other specimens are much smaller, they are partly overgrown by a 
dark-greyish sponge-like creature, partly naked, coloured dirty white or reddish. 
IV. Stat. Jedan-islands — about the same locality from which the specimens from Station 
273 were taken. 
Several small specimens, nearly all broken, apparently young, and certainly not full- 
grown animals. 
The shape of the shell is more conical, the orifice is in consequence smaller, distinctly 
toothed in one, less distinctly in another specimen. The colour is pale red, with darker red 
longitudinal lines. The radii are narrow, their upper edges oblique. 
These are small specimens: the greatest diameter of the largest specimen measures 
at the most 8 mm.. 
The shape and the structure of the opercular valves of the specimens of the different 
localities show great resemblance and correspond almost exactly to Darwm’s description. 
The scutum (Pl. XV, fig. 17a and c) is plainly striated longitudinally, the striae 
dividing the prominent lines of growth into squarish beads. Internally, the articular ridge is 
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