1893, THE GREAT BARRIER REEF OF AUSTRALIA. 459 
Mr. Saville Kent has succeeded in demonstrating the practicability 
of pearl-shell farming. 
An interesting and curious chapter deals with the Béche-de-mer 
or sea-cucumber fisheries. The food of the sea-cucumbers consists 
almost entirely of foraminifera which are swallowed in combination 
with large quantities of shell and coral sand. So physiologically the 
sea-cucumbers are the earth-worms of the sea, and pass through 
their bodies immense quantities of material in process of getting the 
scanty food substances contained in it. 
The animals are prepared entirely for the Chinese market. They 
are collected by hand in sacks at low water. Immediately on their 
arrival at the curing stations they are placed in large cauldrons of 
water and boiled for twenty minutes. They are then split open, 
gutted, partially dried, and finally smoked, the favourite wood being 
that of the red mangrove (Rhizophora mucronata). The prepared 
animals should be perfectly dry and crisp. Mr. Saville Kent does 
not, unfortunately, give further directions in the matter, though one 
would have liked to know the recipe for their final cooking, and any 
commendation or otherwise of their flavour. 
Little seems to be known of the rate of growth of these Holo- 
thurians. A good many forms are present. The cotton-spinners 
have no commercial value ; many others from the soft texture of their 
tissues cannot be cured. The author sent a complete set of specimens 
to the British Museum, where they have been described by Professor 
Jeffrey Bell. Holothuria mammuifera, called by the appetising Chinese 
name Se-ok-sum, appears from its market price to be the surest tickler 
of the Celestial palate, but Actinopyga obesa, under the name of Hung- 
hur, runs it close. 
While the Béche-de-mer fisheries have yielded an average of 
£23,000 a year, the Queensland oyster fisheries produce only about 
£8,000 a year. The oyster is Ostvea glomevata, the ‘rock oyster.” 
Other forms are quite edible and wholesome, but have not yet secured 
a market. The oysters occur in the tropical waters, and so come into 
the Barrier Reef fauna, but the actual fisheries are, for the most part, 
south of the reef. Ostvea glomevata has a number of well-marked 
varieties. The shallow-water forms are the most typical, and have 
luxuriantly frilled and convoluted marginal borders, and bright 
colours. The deep-water varieties have a smoother and more 
ponderous form, often an abnormally elongated contour, and are 
much less conspicuously coloured. 
The old travellers’ tales are realised, and in the region of the 
Barrier Reef oysters are to be found growing on trees. That is to say, 
one of the most favoured habitats of the ‘‘ rock oyster” is the exposed 
roots and respiratory shoots of the white mangrove (A vicennia officinalis.) 
The oyster has many enemies. A small boring whelk (Uvosalpinix 
pavig) does immense damage, especially among the young oysters. 
Mr. Saville Kent seems doubtful as to whether or no the star-fish 
