156 JUNE. 



of seven. They cling about th'e body of the mother, 

 and are carried by her in her rovings with affecting 

 solicitude. 



About the sloping ledges of low -lying rock, especially 

 those which are covered with young mussels, so closely 

 that between their blue-black shells, packed and tied 

 together with byssus-threads, you can scarcely thrust a 

 penknife, we very commonly see slender Worms of a 

 vivid grass-green hue gliding in and out. Their move- 

 ments are very graceful, and if we examine them closely, 

 we discern the presence of a multitude of minute points 

 along each side of the body, which in turn are thrust 

 out and as quickly retracted. If we put the little crea- 

 ture into a vase of water, we see fresh powers and organs 

 of locomotion ; for the back bears a double series of 

 leaf-shaped fins, overlying one another, which act as 

 broadoars rowing the lithe and graceful worm through 

 the sea. 



This species 1 is not more than three inches in length ; 

 but there is another 2 much less common, which is larger, 

 richer in colours, and altogether a finer species. A speci- 

 men which I lately found was about a foot in length 

 when crawling, and nearly a quarter of an inch in width. 

 The whole body was divided into distinct segments, 

 which in this individual were about two hundred and 



1 Phyllodoce viridis. 



/'. laminosa, represented in the middle and right of Plate xviil. 



