152 THE VICTORIAN NATURALIST 



low-lying plain, often marshy, stretching away to a series of hills 

 some miles inland, of which the highest is known as Sea 

 Elephant Hill. Through the plain wanders the Sea Elephant 

 River, the largest stream of water on the island. Along the 

 shore the shells of pinna were extremely abundant at high- 

 water mark, and amongst those just cast up two or three con- 

 taining the living animal were to be found. Haliotes was 

 abundant, together with oyster-shells, the presence of the latter 

 being due to the existence some distance out of an oyster-bed. 

 The shore was thickly strewn with kelp, though this was not so 

 plentiful as on the west coast, and a species of echinus was 

 especially abundant. In addition to those mentioned a few 

 other shore lamellibranchs were to be found, but there was a 

 marked absence along this whole coast of gastropods, except on 

 the shore just opposite to Sea Elephant Island, in which part 

 the dead shells of turbo were abundant. Along the sand the 

 hooded dottrell was everywhere to be seen, and, being the 

 breeding season, its nest, a little ho low of sand, near high- 

 water mark, was frequently found, containing one, two, or three 

 eggs. The Pacific and silver gulls were plentiful, together with 

 the pied and sooty oyster-catchers. The sand above high- 

 water mark also was lined with a great variety of the skeletons 

 of horny sponges, varying from a few inches to a yard in 

 length. 



Striking across the sand-banks we came on to the broad 

 plain bef^e mentioned, covered with heath, and bracken fern, 

 and low scrub. It looks very much as if it had been once the 

 bed of a large lagoon, and, in fact, the Sea Elephant River now 

 broadens out at its mouth into a wide, shallow estuary. A rise 

 of two feet in the river would put a large tract of ground under 

 water. We followed up the river for some distance, and found 

 large flocks of black swans, two of which were shot and 

 served us for dinner, cooked in the hunter's hut, which we 

 reached after fording the stream on horseback. 



The bed of the estuary, which was bare when we crossed, is 

 covered by an innumerable quantity of small black gastropods, '^'' 

 crawling about in all directions, and the river channel near the 

 mouth and its sandy banks were simply one large cockle (as 

 the shell is called) bed. It was curious to find these molluscs 

 living when alternately they are bathed in salt and fresh water 

 — salt at high, and fresh at low, tide. Not only this, but along 

 the coast there was nothing at all comparable to this large, 

 crowded bed of molluscs in the estuary sand, and it was easy to 

 realise how a sudden flood, bringing down mud from the land, 

 would at once cover and kill the molluscs, and how, in course 

 of time, a highly fossiliferous stratum would be formed just in 

 this particular spot. In all the surrounding parts of similar age 

 no such fos sils would be found, and, in fact, very few of any 



* Ophicardeliis cornea. 



