476 HOLOTHURIA; TREPANG. GEOLOGICAL DISTRIBUTION. 



the north coast of New Holland ; and was informed that sixty 

 proas, carrying one thousand men, had left Macassar two months 

 before on an expedition to that coast, the object of which was 

 the collection of trepangs for the Chinese market. The trepang, 

 beche de mer, or sea-cucumber, is no other than a Holothuria, 

 which is extremely abundant on that coast ; in shallow water 

 the animal may be taken up by the hand ; in deeper water it is 

 obtained either by diving or spearing. In order to preserve the 

 edible portion of it, the body is split down one side, boiled, and 

 pressed with a weight of stones, then dried in the sun and stowed 

 away in bags. About a thousand of them make a picol, which 

 is equivalent to 1331bs. ; and 100 picols are a cargo for a 

 proa. It would seem that European traders have now become 

 alive to the value of this traffic ; for there are regular establish- 

 ments in different parts of the Dangerous Archipelago, for those 

 who go beche-de-mer-ing, as the employment is commonly termed. 

 After exhausting the supplies furnished by one island, they pass 

 on to another, and usually complete their cargo within a few 

 weeks. The quantity annually sent to China from Macassar, 

 which is the principal market of the trepang, is usually about 

 7000 picols, or 416 tons ; the price varying from 8 dollars a 

 picol to 115, according to the quality. There is also a consider- 

 able export of trepang from Manilla to Canton. The Sipuncu- 

 lus, also, is used as an article of food in China and Japan. 



1116. The Geological position of the different groups of 

 Echinodermata presents us with many points of great interest. 

 No remains of any of them can be traced in the very oldest 

 fossiliferous rocks ; but, judging by the abundance of the skele- 

 tons of Crino'idea in the limestones of the Transition series, the 

 animals of that group must have been among the most numer- 

 ous of the larger inhabitants of the ocean, at the time these strata 

 were deposited. So abundant are they, indeed, that they may 

 be almost said to constitute those thick and extensive beds of 

 Transition limestone, which, from the wheel-like form of the 

 separate joints of the Encrinite stems, are termed Entrochal 

 Marble. " The substance of this marble," says Dr. Buckland, 

 "is often almost as entirely made up of the petrified bones of 



