BY THE SEA. II3 



the shells are produced, or how the cases in 

 which the various species live, have been moulded 

 into such a variety of curious and grotesque 

 shapes, so brightly polished and so exquisitely 

 marked and colored. 



But there are, on these rocky bottoms, certain 

 kinds of moUusks, without even a trace of arm- 

 orial bearing, that appear to thrive very well, not- 

 withstanding the heavy beating and rolling of the 

 waves. Turning over a rock which is fairly bris- 

 tling with the short filaments of hydroids, and 

 painted with numerous circular, closely-adherent 

 purple patches of sea-scurf, I discovered in one 

 of the little depressions what appeared to be a 

 small lump of flesh. As soon, however, as it was 

 placed in a jar, this shapeless mass at once came 

 to life and revealed its real nature. It was a 

 naked mollusk or sea-slug and one of the most 

 conspicuous species found on this coast. Its pink 

 foot stretched to its full length was narrow, and 

 as it slowly glided along the glass sides, its edges 

 were constantly curving inward as if perplexed 

 with the strange surface on which it moved. On 

 its mottled, dark-purple back, were arranged two 

 rows of branchiae or gills, resembling miniature 

 trees or shrubs, which swayed in the water, like 

 branches in the wind. The pair nearest the feel- 

 ers or antennae, which were also branched, were 

 much stouter and more upright than the others, 



