Sea Shel 
of New 
ls 
Zealand 
Plate V 
No. 1-la. 
Plate V 
No. 2-2a. 
Plate II 
No.6 
ACMAEA STELLA (akme, a point; stella, a star).— 
A strongly-ribbed, somewhat flattened whitish limpet, with 
a laciniate or fringed margin, or one in which the free 
ends of the ribs project beyond the general outline. The 
apex is situated towards the front. Roughly speaking, 
there are about three main ribs extending from the apex 
to the margin in front and four behind, while there are 
one, two, or more shorter ribs between them, extending 
from the margin, but not reaching the apex. The interior 
is bluish white with a brown centre and a ring of brown, 
or dotted brown bordering the margin; the tips of the 
ribs are white. The colours are more or less blurred, and, 
being highly glazed, the interior has all the appearance of 
artistically decorated porcelain. It is about one inch in 
length by three-quarters of an inch across. Found on surf- 
beaten rocks. 
Mount Maunganui; Wellington Heads; Island Bay; 
Cook Strait; Taumaki Island. 
ACMAEA STELLA var. CORTICATA (acme, a 
point; stella, a star; corticata, having a cortex, rind or 
band resembling bark)—This variety is distinguished 
from the species by the smaller size and the disappearance 
of the seven primary ribs, all the ribs being of equal 
strength, though differing in length as the apex is ap- 
proached. The margin is not laciniate or fringed. The 
internal colours are practically similar. 
No doubt it is precisely the same animal that produces 
both the shell of the species and of the variety, for when 
one has made careful observation of the growth and en- 
vironment of the many kinds of limpet it will be found 
that rough rocks almost always tend to foster the growth 
of rough shells, and smooth rocks smooth shells. 
North and South Islands: Mount Maunganui; Dunedin; 
Chatham Islands. 
HELCIONISCUS DENTICULATUS (helcion, a breast 
collar; denticulatus, furnished with little teeth) —A large, 
solidly-built and highly-decorative limpet of a dark brown 
colour, with about twenty-two strongly-marked principal 
ribs reaching almost to the apex. A similar number of 
somewhat smaller ribs alternate with them and extend up- 
wards from the margin for about three-quarters of the 
distance. All the ribs are crossed by concentric flounces, 
more marked at the margin and gradually becoming smaller 
as the apex is approached. Internally the central area is of 
a uniform bright chestnut colour, the remaining portion 
being of a bluish grey with a slightly metallic lustre. This 
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