1893. THE GREA T BARRIER REEF OF A U ST R ALIA . 459 



Mr. Saville Kent has succeeded in demonstrating the practicabiUty 

 of pearl-shell farming. 



An interesting and curious chapter deals with the Beche-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 nmcronata). 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. Holotkuvia mammifera, called by the appetising Chinese 

 name Se-ok-sum, appears from its market price to be the surest tickler 

 of the Celestial palate, but Adinopyga obesa, under the name of Hung- 

 hur, runs it close. 



While the Beche-de-mer fisheries have yielded an average of 

 ^23,000 a year, the Queensland oyster fisheries produce only about 

 ;^8,ooo a year. The oyster is Ostrea glomeraia, 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. Ostrea glomeraia 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 ojficinalis.) 



The oyster has many enemies. A small boring whelk [Urosalpinix 

 pavia) does immense damage, especially among the young oysters. 

 Mr. Saville Kent seems doubtful as to whether or no the star-fish 



