222 BY THE DEEP SEA. 



The Grey Top (T. cinereus] is variable in colour. Usually 

 it is a dull yellowish grey, with inconspicuous dark zigzag 

 marks upon it ; sometimes the ground colour is pinkish-white, 

 with decided pink markings, which present a checkered 

 appearance. There is a deep and wide umbilicus. In Trochus 

 zizyphinus there is no umbilicus, and in the large Painted 

 Top (T. magus), again, there is a very wide one. This last- 

 mentioned species lacks the smoothness of outline exhibited by 

 the other two, its whorls being more boldly ridged at their 

 junctions (suture]. The animal has the head-lobes largely 

 developed, and it is brilliantly and variously coloured ; hence 

 its name. The Tops are vegetable feeders. 



On our South-western shores, when strong winds have blown 

 from the S.W. for days together, there are borne to us on the 

 waves, and wrecked upon our beaches, singular sea-snails from 

 the mid-Atlantic. There the Violet-shells (Tanthind) float in 

 myriads, and consume the still more plentiful " Sallee-man" 

 (Velelld), a Jelly-fish we have mentioned in a previous chapter. 

 There are many singular features about this lanthina. Like 

 a shipwrecked mariner, it constructs a raft, secreting glutinous 

 material from the foot, in the form of many air-chambers 



VIOLET-SHELL, RAFT OF VIOLET-SHELL. 



cemented together, and bearing beneath a large number of 

 egg-capsules. The shell is of somewhat similar shape to that 

 of the Tops, but with a much larger mouth. Its material, too, 

 is so thin it can almost be seen through ; and on the upper 

 part it is white, whilst beneath it is coloured violet, whence 

 its names. The animal has its head produced into a thick 

 muzzle, with a pair of tentacles and a pair of eye-stalks, 

 but no eyes. The breathing organs are two plume-like gills 

 which protrude from the shell. 



