appearance, though in many instances the colour is uni- 
formly greyish brown. The under surface is fairly flat, 
similarly sculptured, but with a more regular disposal of 
the brown-coloured spots, which are entirely confined to 
the ribs or cords. In the centre of the base is a deep coni- 
cal or funnel-shaped excavation, which is typical of the 
species. The interior is pearly. Found just below or near 
low-water mark. It is five-eighths of an inch high and 
rather more in width. 
North and South Islands: Hauraki Gulf; Mount Mau- 
nganui; Chatham Islands. 
TROCHUS VIRIDIS (trochus, a hoop; viridis, green). 
—This Top shell is almost a perfect cone, with a base 
nearly flat. It is of a greyish green or old putty colour; 
some of the juvenile shells having the two or three upper 
whorls of the spire of bright rose pink. The sculpture con- 
sists of ropes of beading which wind round the entire shell; 
large beads at the top of each whorl and round the angle 
of the base, with smaller beaded rows in between. The 
under surface is yellow, with numerous ribs, large in the 
middle, and gradually becoming smaller and less distinct 
towards the outer edge. The interior is pearly. It is about 
three-quarters of an inch in height, and the same in width. | 
Found living on rocks at extreme low water. 
North and South Islands. Mount Maunganui; Chatham 
Islands. 
MONODONTA AETHIOPS (monos, one; odous, odon- 
tus, a tooth; Aethiops, Ethiopian, black).—This is a thickly- 
built purplish-black spiral univalve, tessallated or chequered 
with white between the grooves, which run spirally round 
the whorls. The upper whorls are rounded and large in 
proportion to the whole structure, resulting in a top-heavy 
appearance. The interior of the mouth is white, thinning 
off to nacreous or pearly; the outer lip is black, the mouth 
reinforced with an extra thickness of white shelly material, 
spoken of as callus. The shell has three coats, the outer 
one black, the internal lining nacreous, and the middle one 
a rich malachite green; though why it should be so is diffi- 
cult to say, as the green colour is completely hidden, and 
can only be seen on a very worn specimen or one that is 
broken. The columella has a tubercle or tooth-like emin- 
ence upon it, which accounts for the generic name mono- 
donta, and is to be seen more or less marked in all the 
species. The M. Aethiops is a common member of the 
family, and is found on rocks between tide marks. It is 
23 
Plate VI 
No. 16 
Plate VI 
No.8 
Sea Shells 
of New Zealand 
