The South Justralian Naturalist. 
19 . 
interior. Never two are found alike. It adds laminae in regular 
layers to the interior coating, and the age of the creature may 
be judged from the number of these laminae, or plates. It at- 
taches itself to the crevice of a rock or to the sand by means of 
a “byssus ” a beard of very fine cilia, or hairs. From these hairs 
a fine silk is spun. The organism is very stationary for the rest 
of its life. By means of a siphon on the lower part, the sea water 
is drawn in. The organic and mineral matter needed is retained 
and the waste material, mostly pure water, is ejected by the 
upper siphon. Thus this lowly organism plays an important part 
in purifying the waters of the ocean. Oyster culture is largely 
carried on in the East, and hundreds of thousands of pounds are 
thereby gained; in other countries it forms one of the chief marine 
industries. Several specimens of Fasciolaria were picked up, in- 
cluding coronata, Mr. Kimber described the process of repro- 
duction of mulluscs. The eggs are retained until the embryonic 
shell is formed, when they are ejected. The cilia help them to 
move about till a suitable soot is found. It then spins its “bys- 
sus,’’ and burrows in the sand, or attaches itself to a crevice in 
a rock. If the crevice is not large the shell conforms to the shape 
of the cavity. The Paphia galactites lives in the sand, subsisting 
on the roots of seaweed. The Chama is beautiful, as is also the 
Pecten (lady’s haircomb), or Chlamys hifrons (double- fronted 
cloak). This species moves in a ziz-zag by opening and closing 
its valves. A little crab makes itself at home inside the shell, 
affording another Instance of commensalism (common table) so 
common among the mollusca. The Phasianella australis was 
highly valued when first sent to England, fetching as much as 
£3 a shell. The Polinces conica is a carnivorous gasteropod, bor- 
ing tiny holes in the shells of other species and sucking the juices. 
A shell was found with a tiny hole drilled through the upper coat, 
evidently the work of one of these carnivorous animals. Polinices 
seems to be able to track Its prey by scent. The Cardium tenui- 
costatum (common cockle) is abundant in the southern seas, 
being found in heaps like seaweed, at Port Willunga. 
VISIT TO SIR WILLIAM SOWDEN’S, GLEN OSMOND, 
SEPTEMBER 5th. 
Members were invited to Sir William Sowden’s to examine 
the museum of curios collected by him in all parts of the world. 
Their bulk is so great that Sir William has been compelled to put 
up a special building for their accommodation. The visit of the 
Society was the official opening of the new building. The collec- 
tion was most interesting and Sir William’s informative explana- 
tions added greatly to the pleasure of the party. 
