NUCULA. 143 



Forbes obtained it at depths varying from 45 to 145 

 fathoms. Bronn and Philippi have described it as a 

 fossil of the Subapennine tertiaries ; and I have found it 

 in upper miocene strata at Biot near Antibes. 



This is the largest British species of Nucula. It can 

 hardly be the N. decussata of Sowerby's f Conchological 

 Illustrations/ because the description and figure do not 

 answer to our shell, and that species is stated to have 

 come from the Gulf of Guinea. It may be his N. rugu- 

 losa, which is said to be of the size of N. nitida, although 

 the locality is not mentioned. At all events Bronn's 

 name has the precedence of many years over those of 

 Sowerby. Philippi described, in the first volume of the 

 ' Sicilian Testacea/ the present species under the name 

 of N. Polii. Bronn^s diagnosis exactly agrees with our 

 shell ; and he justly observes that it is larger and 

 broader than A 7 , nucleus. In the l Proceedings ' of the 

 Zoological Society for 1856, another species from New 

 Zealand has been called, by Mr. A. Adams, N. sulcata. 



2. N. nu'cleus*, Linne. 



Area nucleus, Linn. Syst. Nat. p. 1143. N. nucleus, F. & H. ii. p. 215, 

 pi. xlvii. f. 7, 8, and (animal) pi. P. f. 4. 



Body suboval, cream-colour, mottled with flake-white: man- 

 tle having a plain margin : gills triangular and elongated, 

 finelv striated on the outer and inner surfaces, and of a brown 

 colour ; the upper lamina of each pair is by far the larger of 

 the two, and entirely covers the other : lips pendulous, and 

 transversely striated, each of them folded inwards or doubled : 

 foot oval, pale yellow, deeply serrated at the margin, and ex- 

 hibiting about fifty denticles. 



Shell like that of the last species in shape, but much smaller, 

 shorter, and more tumid, as well as more triangular in con- 

 sequence of the posterior side being less produced : sculpture, 



* A small nut. 



