THE T ASM A NIAN NATU R A LIST. 
77 
The sand worm (Fig. 13) is found between high and low tide, 
below stones or burrowing in the sand. It varies a great deal in length, 
from \ inch up to 3 or 4 inches. It is very active and wriggles in the 
hand tremendously. A cursory examination of the body shows that it 
is in the shape of a long cylinder, somewhat flattened from above down. 
A close look brings forward the fact that this long body is made up of 
a great number (about eighty) of rings running right round the body 
and separated from one another by grooves. Each of these rings bears 
a part of legs which are much like the legs of a caterpillar, except that 
instead of the hooks or claws of the caterpillar, the legs of Nereis bear 
'each a bundle of hairs; hence these animals allied to Nereis form a 
class called Chaetopoda (hairy-footed). To examine Nereis properly, it 
would be as well to put a large specimen in a saucer of sea water and 
look at it with a magnifying glass. You will, then, see that the head end 
bears a number of feelers, six on each side, while the tail end only has 
two of these (if by any means a portion of the tail of the ‘sand’ 
worm is broken of! it does not die but is able to repair the damage done 
and still live on). Close watch kept on the living animal will show, 
also, very probably the thrusting out of the jaws. The mouth is an 
opening on the lower side of the head and it opens into a long tube 
running right through the animal, instead of the jaws being a part of 
the mouth, they are set far back in this tube, and when wanted to seize 
upon food, a portion of the tube is turned inside out like a stocking, and 
pushed through the mouth until the jaws lie outside. They can then be 
•brought back to their former position. Each jaw is hook-shaped and 
made of a brownish, horny substance Nereis is a quite highly organised 
animal It has a brain and nervous system, and a system of blood 
vessels filled with red blood. The main blood vessels can be easily 
seen ; one runs along the upper side, another along the lower. 
There are numerous relatives of Nereis, some of which swim or 
'crawl freely, while others live in tubes. There is a common worm near 
the Hobart wharves, called Terebella , which live in a tube made of mud 
from which it merely projects its head. On the head is a great number 
of feelers and tentacles, while the legs and hairs, through the animal 
.living in a tube, have become useless and reduced merely to a few bristles. 
Another member forms the hard limy little tubes found on rocks, 
and which almost cover them sometimes. A worm which causes disease 
in oysters also belongs to this group of hairy footed worms. 
The common earth worm is also nearly related to Nereis. This 
creature agrees in a good many points with Nereis , but its habit of 
•crawling through narrow tubes in the ground has rendered legs useless 
and unnecessary to it. All that represents the legs are a few hairs or 
bristles scattered over the body, and these enable the worm to obtain a 
.purchase on the sides of the tube in which it lives. 
Leeches ( Hinidinea ) are a peculiar group of worms, some of which 
live in the sea and live on the blood of fishes and other marine animals. 
They all have, in connection with the digestive system, a large crop 
which is capable of being greatly enlarged with the blood obtained. 
