Chap. XI.] MIXTURE OF LAND AND SEA FORMS. 235 



nre here brought with those only occurring inland, is of great 

 interest from a geological point of view ; it recalls at once to 

 the mind such mixtures of marine and terrestrial animal 

 remains as those occurring in geological deposits, such as the 

 Stonesfield beds. 



Here is a narrow strip of sea-water, twenty miles distant 

 from the open sea ; on a sandy shallow flat, close to its head, 

 are to be seen, basking in the sun, numbers of Sting-rays 

 {Trygon), a kind of skate provided with a sharp saw-edged 

 bony weapon (the sting), at the base of its tail. All over these 

 flats, and throughout the whole stretch of the creek, shoals of 

 Grey Mullets are to be met with ; numerous other marine fish 

 inhabit the creek, some growing to 150 lbs. in weight, and 

 often caught weighing as much as 60 or 80 lbs. A Diodon or 

 Trunk-fish is amongst the fishes. Porpoises chase the mullet 

 right up to the commencement of the sand-flat. 



At the shores of the creek the rocks are covered with masses 

 of excellent oysters and mussels, and other shell-bearing mol- 

 lusks are abundant, whilst a small crab is to be found in 

 numbers in every crevice. 



On the other hand, the water is overhung by numerous 

 species of forest trees, by orchids and ferns, and other 

 vegetation of all kinds ; mangroves grow only in the shallow 

 bays. The gum-trees lean over the water in which swim 

 Trygons and mullets, just as willows hang over a pond full of 

 carp. One could sit on a gum-tree and fish for sharks. The 

 sandy bottom is full of branches and stems of trees, and is 

 covered in patches here and there by their leaves. 



Insects constantly fall on the water, and are devoured by the 

 mullets. Land birds of all kinds fly to and fro across the 

 creek, and when wounded may easily get drowned in it. 

 Wallabies swim across occasionally, and may add their bones 

 to the debris at the bottom. 



Hence here is being formed a sandy deposit, in which may 

 be found Cetacean, Marsupial, bird, fish, and insect remains, 

 together with land and sea-shells, and fragments of a vast land 

 flora ; yet how restricted is the area occupied by this deposit, 

 and how easily might surviving fragments of such a record be 

 missed by a future geological explorer ! The area occupied by 

 the deposit will be sinuous and ramified like that of an ancient 

 river-bed. 



The inlet being so extremely long and so narrow, although 

 the rise of the tide is two feet or more at the head of the creek, 

 the interchange of water with the ocean is very small ; the 

 water in the upper parts of the creek is merely forced back to 

 a higher level by the tide below at flood-tide, and similarly 



