How this species comes to be specifically labelled “slightly 
beaked” I have no idea, for there is nothing in the shape 
of the shell remotely resembling a beak. Common on rocks 
between tide marks, along the Northern coasts of New 
Zealand, as far south as Tauranga. Omokoroa; Mount 
Maunganui. 
Note.—Although none of the Monodontas, at first 
sight, are particularly attractive, they are well worth at- 
tention, and there are no species that I would sooner com- 
mend to the notice of beginners than this group. In the 
first place, they are all fairly plentiful, and being found 
invariably between tide marks, at all seasons, are the easiest 
shells to collect. Seven of the nine native species occur 
among the rocks at Mount Maunganui alone, and they are 
equally numerous in other parts of the Dominion. The minor 
differences that mark the species are definite enough, once 
they are known, and the lesson in observation entailed in 
recognising and separating the various kinds may prove so 
interesting and instructive that the casual collector may, 
through his experience with these shells, graduate uncon- 
sciously into a scientific naturalist. 
CANTHARIDUS DILATATUS (kantharis, an irides- 
cent beetle; dilatatus, dilated, expanded).—A smooth, 
rather solidly-built, spiral univalve, about three-eighths of 
an inch in height, of a conical shape, with a pointed spire, 
and the body whorl somewhat dilated or splayed outwards 
as the aperture is approached. The mouth is almost round 
and the outer lip is fairly thick. In colour it is pinkish, or 
brownish pink, or brownish purple, sometimes adorned with 
short white streaks in the region of the suture. The suture, 
by the way, is the line of union between two adjoining 
whorls. In some specimens, white zigzag bands are longi- 
tudinally arranged on the last few whorls. The interior is 
highly iridescent and of a vivid and fiery green, or a 
flashing blue. The sculpture consists of numerous and 
very fine spiral striations close together, but on the base 
a little further apart. Found on seaweed in rock pools in 
rather sheltered situations and in association with its some- 
what more prolific relative, the C. sanguineus. 
East and west coasts of the North Island. Hauraki 
Gulf, Mount Maunganui; Auckland Harbour. , 
CANTHARIDUS OPALUS (kantharis, an iridescent 
beetle ; opalus, an opal).—A tall spiral univalve with almost 
straight outlines, and the body whorl at the base roundly 
or bluntly angled. The colour of the body whorl, and that 
immediately above it, is lilac, with purple zigzag markings 
2/ 
Plate VII 
No. 4 
Plate VII 
No. 3 
Sea Shells 
of New Zealand 
