I 87 I 
•head') of a Tapeworm. Closely allied to the Pearl-Oyster is 
the Hammer-Oyster (MttHeus allws), thus called from its curious 
T shape. The various species of the Thorny Oyster {Spondv' 
las) are often brilliantly coloured. They have their name from 
the spine-like processes of the shell. Of Scallop Shells there 
is a great variety, includini? forms beautiful through their scuip- 
ture and colouring. They are generally marked with radiating 
ribs^ but others are smooth. To the latter belongs Pecten 
japmiicus. One of its valves is terracotta-red* marked with 
darker concenlrical lines which are as regular as if they had 
been painted. The other valve is white. 
Eultvnellibrdnchiih This order is larger than the pre- 
ceeding one and includes first of all the Edible Oyster [Ostraea 
eduHs). Oysters of various species ure found on rocky coasts 
all over the world, the Arctic regions excepted. The Singapore 
market receives its chief supply of them from Muar, but some 
also from the West Coast of Sumatra. The Muar Oysters are, 
from information kindly furnished by Mr. Makepeace, found in 
the Ued of the river, some near the town of Banda Maharani, 
others nearer the mouth. The latter are a bigger and better 
quality and are reserved for the Sultan and the officials. The 
Oysters are found at a depth of 15 to 20 feet, on muddy bottom. 
They are collected at low tide by men who go over the beds in 
small kolehs and dive for them. Their price in Singapore is 
$1 a bag, in Muar only 40 to 50 cents. Specimens from there, 
presented by Mr. C. H. Clarke, are exhibited. To the Oyster 
tribe belongs also Pinna, a large shell of triangular shape, 
common locally and usually found sticking in the mud. Its 
projecting razor-sharp edges inflict serious wounds to any 
one stepping upon them unwarily. Most freshwater bivalves 
belong to this order, like Cyclas and Pisidiunu both of 
which are ver>' small, and the much larger Unio and 
AnodonUi. More than one thousand species belong to the 
Freshwater Mussel Unio. It differs from Anodonia by its thick 
shell and toothed hinge. Speciniens of Unia sp., from Raub, 
Pahang, presented by Mr. Rostados, are exhibited, A marine 
shell of brilliant violet colour is Mactra violacea, and one 
showing delicate sculpture is Venus ciatkrata, from Blakang 
Mali. The Cockles belonging to the genus Cardium 
abound in shallow water buried in the sand. An exquisite form 
is the heart-shaped Cardium cardissa. Closely allied to the 
Cockle is the largest of all living Bivalves, the Giant Clam 
(Tridacna gigantea), Thts species abounds on the Great 
