i 
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H. M. S. “Siboga’’ collected about a dozen specimens of this characteristic species. The 
larger specimens have a basis of 17.5 X 14 mm., and the greatest height measures about 17 mm. 
They are found attached to shells of different Gastropodous Molluscs: a /wszs-like species, and 
others, all more or less broken. Some of the specimens are crowded together so as to hinder 
each other in their development, others are isolated. The species was collected at: 
Stat. 12. March 14, 1899. Lat. 7° 15’S., Long. 115° 15’.6 E. Depth 289 m. Bottom: mud and 
broken shells. 12 specimens of various sizes. 
Stat. 95. June 26, 1899. Lat. 5° 43.5 N., Long. 119°40'E. Depth 522 m. Bottom: stony. 
One small specimen. 
Stat. 260. Decbr. 16 and 18, 1899. Lat. 5° 36.5 S., Long. 132°55'.2 E. Depth 90m. Bottom: 
sand, coral, and shells. One small specimen, the largest diameter of the basis of 
which measures 6.5, the smallest 5 mm. 
General Remarks. The structure of the labrum with the row of small teeth along 
the edge is interesting, in so far as such small teeth are likewise seen along the edge of 
other deep-sea species of the genus Aa/anus, and the nearly-related genus Hexelasma. The 
form and structure of the opercular valves makes it highiy probable that the small specimen 
(Pl. XVII, fig. 4) collected at Station 260 also belongs to this species. This would be a new 
instance of the case already stated, that forms with deep-sea characters occur at depths of 
about 100 metres or even slightly less. The determination of the small specimen from Station 
95 is not quite certain: it is a very incomplete specimen, without opercular valves. Its surface 
is corroded; the shell has no pores but distinct longitudinal ribs along the interior surface of 
the compartments, and as the shape of the radii and alae is the same, and the basis cor- 
responds also, I think it is not too risky to place it here. 
8. Balanus maculatus n. sp. Pl. XVII, fig. 7—13. 
Shell conical, dirty white with longitudinal stripes of pale red and more or less numerous 
red spots. Carino-lateral very narrow. Radii extremely narrow, with the summits very oblique, 
alae somewhat broader, with the summits rounded. Scutum plainly striated longitudinally; tergum 
without longitudinal furrow, with the spur broad, its hinder margin rounded, sloping into the 
basal margin. 
This species also resembles 2. amaryllis in several respects. There is quite a number 
of specimens in the collection; most of them are attached to wood, a lot of smaller specimens 
were found attached to a piece of stone. 
The general shape of the shell (Pl. XVII, fig. 7) is conical, with the rostrum slightly 
convex, and the carina straight. The orifice is toothed, but only superficially; it is medium-sized, 
pentagonal. Its largest diameter is not quite half the largest diameter of the basis. No chiti- 
nous membrane over the shell. It is smooth, dirty white, with more or less numerous longi- 
tudinal stripes of a greyish-red colour, and more or less distinct spots: either the surface is 
strongly or weakly spotted, or almost entirely white. The red colour is in several specimens 
more distinct along the margins of the compartments, and over the surface of the alae. Here 
and there the longitudinal stripes are crossed by horizontal ones, formed by red dots, which at 
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