SIPUNCULUS. GEOGRAPHICAL DISTRIBUTION. 475 



the Echinus. In some, however, this is replaced by a sort of 

 proboscis, which may be protruded or retracted like that of many 

 Annelida ( 906). So great a resemblance, in fact, do such 

 animals bear to certain species which we find in this Class, that 

 they have been arranged by many Naturalists amongst the 

 Annelida, and their true place may still be regarded as doubtful. 

 Nothing can be imagined that is wanting to complete the con- 

 nection between these two classes, which is established by means 

 of this group. The Sipunculi are seldom found but on sandy 

 shores. They excavate holes in the sand, in which they conceal 

 themselves, occasionally protruding their heads from the orifice. 

 They are much sought after by fishermen, who use them, like 

 the common lob-worm (Arenicola piscatorum\ as baits for their 

 hooks. Some of them attach stony particles to their skin, by a 

 glutinous exudation, so as to cover it with a hard crust, resem- 

 bling that formed by some Annelida ( 911), others take up 

 their abode in the abandoned shell of Mollusca, whilst one or 

 two species are able to excavate a habitation for themselves in 

 the solid substance of rocks and corals. 



1115. In regard to the Geographical distribution of the 

 Echinodermata, it may be stated generally, that all the forms of 

 this Class are represented in nearly every portion of the globe. 

 As in other classes, however, so in this, it would appear that 

 the largest species are found in tropical regions ; but Echini, 

 Asterice, and Holothuria, occur in plenty on our own coasts. 

 Star-fish occasionally abound so much on the shores of France, 

 as to be used for a profitable manure. We have no certain 

 knowledge as to the animals which find in the Echinodermata 

 their regular food. Of the Stellerida, Man makes no other use 

 than that just stated; and of none of the Echinida does he eat 

 any other part than the roe ( 1099). This is also said to fur- 

 nish a large portion of the food of the Salmon during its sojourn 

 in the sea. Of the Holothurice, one species is collected and 

 eaten by the poor inhabitants of the Neapolitan coast ; but there 

 is another which constitutes an important article, not only of 

 consumption, but of regular traffic. Captain Flinders (1803) fell 

 in with a fleet of Malay proas, near the Gulf of Carpentaria, on 



