after strong easterly gales at Mount Maunganui and at 
Opotiki. It has also been recorded from the Manukau 
Heads and other places in both Islands. 
MYODORA BOLTONI (mya, a mussel; dora, a skin, 
a hide; Bolton, the naturalist)—A small white bivalve, 
barely exceeding half an inch in length, and rather more 
than a quarter of an inch from the beaks to the ventral 
margin. Differing from most bivalves, the beaks are 
directed backwards, towards the ligament, The right valve 
is convex externally, and the left valve, instead of being 
flat, as in the M, striata, is somewhat concave or, in other 
words, it bulges inwards slightly. In shape, the valves are 
considerably narrowed at the posterior end, where they are 
cut off abruptly. The dorsal margin in front of the beaks 
is almost a straight slope downwards; behind the beaks 
it takes a sharp inward curve. The ventral border is one 
broadly-rounded sweep. The sculpture consists of fine con- 
centric ribs and grooves, not very pronounced, and at the 
posterior end there is a deep fold on the right valve, com- 
mencing at the beak and descending to the cut-off margin. 
The interior is lined with glistening white mother-of-pearl. 
Found between tide marks, 
Auckland Harbour; Mount Maunganui; Lyttelton Har- 
bour. 
MYODORA STRIATA (mya, a mussel; striata, with 
striae or fine lines)—A fan-shaped bivalve with the angle 
at the hinge, and the ventral border semi-circular. The 
beaks are directed backwards, contrary to the general rule. 
One valve—the right—is convex, and the left one is flat, 
both sculptured with well-defined concentric striations. 
The interior is smooth, lined with mother-of-pearl, white 
and glistening. It is about one and a-half inches long, and 
is often met with on sandy ocean beaches. 
North and South Islands, Mount Maunganui. 
CHAMOSTREA ALBIDA (chama, a bivalve so named 
by Pliny; ostrea, an oyster; albida, whitish).—A curious 
wedge-shaped oyster-like bivalve, with the right valve deeply 
hollowed, attached to rock, and the left valve flat. At the 
hinge the shell is of a whitish yellow, or light brown, the in- 
terior being of a greenish white and slightly pearly. The shell 
1s very thick and strongly built, and is about two and a-half 
inches long. The sculpture consists of concentric lamellae, 
with a slight indication of spiral arrangement, on the left 
valve. There is a single large tooth on the left valve, 
fitting into a corresponding pit in the right valve, and 
115 
Plate IX 
No. 10 
Plate IX 
No. 11 
Plate XI 
No, 18 
Sea Shells 
of New Zealand 
