AND STRUCTURE. 191 



head of fine slender tentacles crowded together in 

 seeming confusion . 



When more carefully examined the membranous 

 disk appears to he really circular in outline; the 

 mouth, an oval orifice with crenated lips, is not placed 

 on a cone ; delicate lines, as usual, radiate from it. 

 The innermost tentacles are planed at about half an 

 inch from the mouth (in a large specimen) ; these 

 are scattered irregularly and loosely; others succeed, 

 more thickly, until towards the margin they become a 

 dense fringe deifying enumeration. The innermost 

 ones are stouter than the outermost : the length of 

 both varies much in specimens of the same size ; — 

 sometimes being not more than one fourth of an inch 

 long, at others thrice this length. 



The whole texture is somewhat pellucid, especially 

 on the oral disk and the tentacles : the outer covering 

 of the body appears sub-coriaceous, though soft and 

 mucous. 



In Weymouth Bay this species is very common, 

 and still more abundant in the deeper water of the 

 offing; both the dredge and the trawl constantly 

 bringing up single specimens and clustered groups. 

 The latter are sometimes very numerous, as many as 

 twenty being not uncommonly crowded on a single 

 oyster-shell. Of course such a group on so limited a 

 space, must include a good many small ones ; gene- 

 rally they are of all sizes, from the giganticjforefather 

 of the family to the tiny great-grandchildren that are 

 scattered round his base, no larger than peas. In 

 general all the members of each group are of the 

 same hue ; as they are I presume strictly one family. 



