74 SAGAETIAD^E. 



which is occasionally broken in front, but always passes off behind in a 



slender wavy line to the margin, where it slightly 



bifurcates. Frequently the ring dilates into an 



undefined spot at each side of the tentacle-foot. 



Sometimes the line passing off to the margin 



can be scarcely discerned beyond the second 



tentacles OF RPHT- row ' and sometimes tQe whole marking seems 



EODETA obliterated. 



(viewed vertically). Mouth. Pure white. 



Size. 



Half an-inch in height, and about the same (or occasionally a little more) 

 in expanse. 



Locality. 



The south and west coasts of England. Low-water mark. Fissures in 

 rocks ; the under surface of stones. 



Varieties. 



o. Candida. The condition above detailed, which I originally described 

 in my " Devonshire Coast" under this specific name. 



13. Xanthosis. Disk assuming various shades of yellow, from a pale 

 chrome or lemon-colour to a deep orange, or even dull vermilion. 



This pretty little species was discovered "by myself at 

 Ilfracombe. It was during an unusually low spring- 

 tide, in October, 1852. Specimens occurred at that time 

 in two localities, having this in common, that in each case 

 they were adherent to the perpendicular or overhanging 

 surface of the cliff, at the very verge of lowest water. The 

 animals were social : in the one case I found three indi- 

 viduals associated ; in the other many dozens, a numerous 

 colony thronging the approximating sides of a narrow 

 fissure that runs far up into the solid rock at the seaward 

 base of Capstone Promenade. A frequent tendency to a 

 pendent posture was noticed ; for even where the general 

 surface of the rock was perpendicular, many of the Ane- 



