a Shells 
“¢ New Yealand 
Plate VI 
No. 21-2la. 
Plate VI 
No. 20 
Throughout New Zealand. Mount Maunganui; Aus- 
tralia; Mauritius; Ceylon. 
RISELLOPSIS VARIA var. CARINATA (rusilla, a 
wrinkle ; opsis, like; varia, spotted, striped ; carinata, having 
keels).—This minute spiral univalve, the largest being no 
more than a quarter of an inch in diameter, is met with on 
rocks about high-water mark, usually in beds of the small 
black mussel. It is of a dingy yellow colour, mottled with 
dark brown, and somewhat flattened; the most conspicuous 
feature being two well-marked keels at the outer edge, As 
the upper whorls and the base are both considerably flat- 
tened, the whole shell may be said to be of tabloid form. 
The shell is particularly liable to be overlooked, not so 
much on account of its small size, but from the fact that 
the rounded keels of a light colour are presented edgeways 
to the observer, and, being on a parallel plane to the mussels 
amongst which they are hiding, it is difficult at first to 
distinguish between the pale curve of the Risellopsis and 
the high light upon the shining black circular margins of 
the mussels; an interesting example of protective colouring 
in nature. 
Throughout New Zealand. Mount Maunganui; Chat- 
ham Islands. 
Note.—The species Risellopsis varia is said to be found 
in the same localities as the variety or sub-species, just 
described, but up to the present I have not been fortunate 
enough to come across a single specimen. 
PLANAXIS BRAZILIANUS (planus, smooth; avis, a 
stem or axis; of Brazil).—A small, very solidly-built spiral 
univalve of amphibious habits; the shell is covered in the 
recent state with a buff-coloured periostracum. When this 
is worn off the shell is seen to be quite smooth, polished, 
almost white, and devoid of all sculpture except a few fine 
grooves round the neck at the base.. The neck is indicated 
only slightly. The spire is rather higher than the height 
of the aperture, which latter is more round than oval, with 
a thick rounded outer lip, and a small notch-like canal at 
the base. Suter states that the specific name is a misnomer, 
as the shell “does not occur on the coast of Brazil,” but 
as the name was applied in the first instance by Lamarck, 
who described it in the year 1822, and no one is likely to 
be mislead by it, there is no real necessity to alter it. It 
1s about five-eighths of an inch in height, and is found at 
the Bay of Islands; Australia; Lord Howe Island. 
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