74 Mr. Montagu's Description of Marine Animals 



decay while the other is alive ; and the addition of any thing 

 offensive produces contraction ; even fresh water. 



GORDIUS ANNULATUS. 



This beautiful worm is of a garnet red colour, with a pure 

 white line along the back, and another on each side, extending 

 the whole length; between these are two rows of minute white spots, 

 commencing about an inch from the head, and extending quite 

 to the posterior end, the extremity of which is rounded and white : 

 the fore part of the head, except the upper lip, is also of that co- 

 lour: at small irregular distances are white transverse lines or bands 

 that encircle the body, some of which are broader than the rest. 



Length, six or seven inches : diameter at the anterior end, one 

 line ; rather less at the posterior. 



This, like the preceding, is capable of great contraction, ex- 

 pansion, and variation in shape ; spreading in some parts, while 

 others rise into swellings : but its more usual form is a little 

 flattened. 



Several of this species were taken in old shells, and amongst 

 coralline, by dredging. In all probability it is not common; other- 

 wise an animal with such strong specific characters could not 

 have been overlooked. 



Sipunculus Strombus. 

 Body rather more taper than cylindric in its contracted state ; 

 but, when extended, the anterior end, for nearly one half its length, 

 is not above half the size of the posterior : it is quite round, and 

 not the least depressed in any part ; the larger end seems less ca- 

 pable of contraction than the anterior ; this latter being endowed 

 with the singular property of retracting or withdrawing itself in- 

 ternally, in the same manner as the common Litnax withdraws the 



ocellated 



