OCELLINA; TURBINOLIA. 197 



strongly grooved in a longitudinal direction, the interspaces or ribs 

 equidistant, smooth, glossy, broader than the furrows, converging 

 towards the narrow base, where some unite, and others are continued 

 to the very point, if not in a slight degree beyond it. Above, the 

 ribs turn over the edge, and are continued into the centre of the en- 

 larged oval cup, forming its lamellae. These are twenty-four in 

 number, alternately longer and shorter, arched, and crenated on the 

 inner margin ; and in the centre of the disc or cup there is a trans- 

 verse lamella, which some of the concentric lamellae are long enough 

 to touch. 



That the Zoophyte must have lived for some time after having 

 become a moveable thing is proved by the ribs being continued 

 beyond or around the point of attachment. 



The specimen which has afforded our description, is five lines in 

 height, and three in the diameter of its top. It was dredged alive 

 by Mr. MacAndrew, and lent me by Professor Forbes, who truly 

 remarks, that it is " a most interesting and beautiful species, the 

 more so as it is certainly identical with Defrance's Turbinolia mille- 

 tiana, found in both the crags." An examination of fossil specimens 

 from Mr. Wood and Professor Forbes, has left me assured of the ac- 

 curacy of this conclusion ; and the fact assumes great interest as an 

 additional illustration of the permanency of species in general. 'Tis 

 a long time since the " coralline crag " was deposited, long enough 

 methinks for any good law to develope its effects in its subjects, 

 and yet this very old Turbinolia has not obeyed the " law of develop- 

 ment," but has steadily maintained, amid the changes around it of 

 very many centuries, its original features, and form, and size, alike 

 careless of human theorems, and insensible to the urgency of its in- 

 nate appetencies and higher aspirations ! I can perceive no difference 

 between the Turbinolia of the crag, and the Turbinolia now living 

 off Scilly, except that the base of the former is less pointed ; and this 

 trivial difference would probably disappear in an examination of a 

 larger series of specimens. I have now seen three recent examples, 

 and they all differ a little in the width of the base. In one fossil 

 specimen, the ribs were undulated on the lower half of the polypidom, 

 the projection of the one rib running into the recessions or bays of 

 the other next it, but this character is inconstant. 



" Michelin, in his ' Polypiers fossiles de France,' figures a species 

 under the name of ' Turbinolia mixta, Defrance MS.,' (pi. 43, fig. 3), 

 from the Paris basin, which is evidently identical with the T. mille- 

 tiana." E. Forbes. Nor is the Turbinolia figured by Mr. R. C. 



