16 
to contain a small percentage of muriatic acid. Such powers have 
some shellfish of dissolving or altering the form of their shells, 
that the Cyprae, or Cowry, our representative of which family is 
the Trivia australis (Plate VII., Fig. 29), not only can dissolve the 
inner part of its shell, but can deposit new layers on the outside. 
This Murex lives on sand in the open ocean, and is found in the 
North Island only. 
MUREX OCTOGONUS (Plate IT.).—Fig2is a slightly longer 
shell than the Murex zelandicus, and, like it, is found only in the 
North Island. But in place of being round or oval, this shell 
is octagonal, from which peculiarity it derives its name. The 
grooves that cross the shell are deep, and between them are small 
curved spines. The shell is thick and solid, the exterior being 
reddish white, sometimes stained with brown. There is a smaller 
variety of this shell, darker in colour and with more numerous 
spines than the photographed specimens shown. 
MUREX EOS (Plate II.).—Fig. 3 is a beautiful pink shell, 
about an inch long. Dead shells only have been found, and a 
good specimen is much prized. None of the Murex family are 
common, and they are seldom found alive. Murex eos, although 
existing in Tasmania and Australia, has so far been found in 
New Zealand nowhere South of the Bay of Islands. 
MUREX RAMOSUS.—Two specimens of this well-known 
Island shell have been found in Tauranga during the last five 
years. One excellent specimen, 8} inches long, was a live shell, 
and is now in the possession of Mrs. T. M. Humphreys, of Tau- 
ranga. An illustration of this shell will be found on Plate X., 
Fig. 10. 
TROPHON STANGERI (Plate II).—Fig. 4 is a rough grey 
shell, with a dark purple interior. It is covered with parallel 
ridges and lines, which are known as varices, very thin and 
close together, and running from the apex to the mouth of the shell. 
It is over an inch in length, and usually found on cockle banks 
in harbours. 
TROPHON AMBIGUUS (Plate II.).—Fig. 5 is in shape 
very like the Murex stangeri, but twice the dimensions, and can 
be easily distinguished, as the varices are much higher and further 
apart; besides which they cross one another at right angles, form- 
ing a perfect network, and the interior is pinkish brown. This 
shell is found on ocean beaches, as well as on cockle banks. 
