134 The South Australian Naturalist. 



Excursion to Outer Harbour, July 14, 1923. — A party of 



members visited the Outer Harbour beach to study '"Shells," 

 under the joint leadership of Messrs. W. J. Kimber and D. 

 Looker. Two sections of beach were explored, one that bor- 

 dered the made-u]) ground at t]ie extreme north of the wharf, 

 and the other the natural beaeh further north. The rocks on 

 the former beach contained many "semi-fossilised'' shells, 

 examples of which could be picked up in the vicinity. This 

 rock was considered to be of very recent origin. A dead cuttle- 

 fish {SepiM apama) picked up along the second beach formed the 

 subject of a very interesting dissertation on the life habits of 

 this decapod. As this name implies, the cuttlefish has ten Teet 

 or tentacles, two of which are much longer than the others. 

 These are used in seizing its prey and bringing it to its beak-like 

 mouth. This fish can swim forwards or backwards, its syph(jn 

 being used for this purpose. When attacked it covers its retreat 

 by ejecting an inky matter, which darkens the water for some 

 distance around. As a furtlier protection, the cuttlefish can 

 change its colour so as t(j blend with its surroundings and escape 

 detection. 



Mr. Kimber dealt with several varieties of shells, and by 

 means of large drawings showed the fish which mad^ the shells 

 and tlieir mode of attachment. The first one {Scutus anatinus) 

 develops a shell oblong in shape, which is almost covered by the 

 animal ; only a small part of the top was exposed. The second 

 one ^^'<i(j((reti(s Incrujatas) was a thickish white shell, which 

 is much smaller than the animal itself. The shell protects the 

 vital organs of the fish. The animal forming the violet shell 

 lives on the surface of the water, and is provided with a wonder- 

 ful raft, on the underside of which the eggs are laid and carried 

 until they are hatched. The young shells emerge from the 

 bottom of the egg and float to the surface to begin life on their 

 own account. The fourth example was the cowrie (Cypraea sp.). 

 Unlike the others, this fish is able to withdraw the whole of its 

 body into the shell. Mr. Kimber referred to the beautiful colour 

 of these shells, and explained that the mantle always covered 

 the shell when it was not withdrawn inside. The won- 

 derful surface and colouring of this shell was the chief reason 

 why it was so much sought after. 



Excursion to Black Hill, July 28, 1923.— A small party of 

 members, under the leadership of the Secretary, Mr. E. H. 

 Tsing. visited Black Hill on Saturday, July 28. The chief 

 interest of the visit centred in the study of the plants of this 

 part of the foothills of the Mount Lofty Ranges. The Mount 

 is a striking object from Adelaide from its height, its steepness, 

 its dark colours, and from the prominence with which a road- 

 way stands out, winding up its steep western side. The party 



