100 



LIFE BY THE SEASHORE. 



FIG. 34. Head and intro- 



of tentacular cirri. The remaining segments bear parapodia 

 consisting of a single branch, with leaf-like ventral and 

 dorsal cirri. The bristles are relatively 

 few in number. In living specimens 

 you will notice the frequent eversion of 

 the capacious proboscis, or introvert, 

 which has no jaws, but bears small pa- 

 pillae. This is an extremely common 

 worm, and one almost certain to be en- 

 countered. Though the colouring is 

 sober, it is a pretty little creature, and 

 repays careful examination. 



The other species mentioned, the 

 paddle -worm (P. lamelligera), is very 

 much larger, and is one of the hand- 

 somest of our British wDrrns (see Fig. 

 33). It has been known to reach a 

 vert (i) of Phyiiodoce length of two feet, but is more usually 



lamelhgera. After Ehlers. , . , ' . 1,1 



twelve inches or under. It is a bulky 

 worm with a flattened body, usually about a quarter of an 

 inch wide, and is green in colour with iridescent metallic 

 tints. It lives beneath stones near low-tide mark, and in 

 many places is not uncommon. Like the preceding species, 

 it has a capacious introvert furnished with papillae, but with- 

 out jaws. The number of tentacles and cirri is the same as 

 in the preceding species, but it differs from this in the shape 

 and position of the dorsal plates. There can, however, be 

 no possibility of confusion between the two species, for their 

 general appearance is very different. 



We shall not consider any other species of Phyllodoce, 

 although others do occur on our shores, but may just notice 

 some points as to the genus as a whole. It is a large genus, 

 and is, indeed, by some authorities split up into sub-genera 

 denned by the characters of the head, but the specific 

 characters are often very indistinctly marked. In Poly- 

 chsetes in general the characters relied on in discriminating 

 species are usually the numbers and characters of the 

 bristles, the characters of the parapodia, and the structure of 

 the head and introvert when this is present. But in the 

 genus Phyllodoce, while some of these points display great 

 constancy, others seem to display much individual varia- 



