244 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



" remain attached to the side of the glass a considerable 

 "time. They are very easily kept in confinement for 

 " years ; but, as with many of their allies, great diminn- 

 " tion of bulk occurs, from deprivation of the natural 

 4k supply of food. When recently captured specimens are 

 " placed in a jar containing injured Annelida, numerous 

 " faecal masses, consisting of the bristles of Nereis pelagica, 

 " and other annelids and digested matter, are found lying 

 '* on the bottom of the vessel, showing how greedily thev 

 " have fed ; a fact, indeed, very easily ascertained by 

 " actual observation. It is also frequently noticed that 

 " specimens confined in vessels along with the deep green 

 " Eulalia viridis assume a similar hue, probably from 

 '" feeding on the rejected debris of those animals, if not 

 k ' upon the latter themselves. In their native haunts the 

 " stones under which they lie are often placed on dark, 

 " muddy, and highly odoriferous sand or gravel, and the 

 " water cannot be otherwise than brackish at the estuary 

 " of a river." 



BODY WALL AND MUSCULAR SYSTEM. 



The outside of the animal is completely covered with 

 cilia, which are borne by long slender cells (PI. II., fig. 3), 

 widest externally where thev carry the cilia, and narrow- 

 ing to a very fine process which is somewhat branched, 

 and is inserted into the basement membrane. They con- 

 tain small elongated nuclei in the more external portion. 

 The larger and more rounded nuclei found in the 

 epidermis are for the most part connected with the large 

 greenish unicellular gland cells occurring all over the 

 skin. These last stain vividly with picric acid or with 

 eosin, and it is probably their contents which give the 

 skin its markedly acid reaction. These two forms of cell 

 constitute the main mass of the epithelium, though it is 



