72 Royal Institution. 



A beautiful pinkish yellow species, without any spots or markings, 

 with the plicae on the fore part undulated and rugulose under the 

 lens. 



Crassatella truncata, a. x\dams. C. testa ovata, com- 

 presstty carneUy pallidlori ad partem anticarriy radiis angustis 

 inconspicuis ornata, incequilaterali, latere antico breviori et 

 rotundato, postico dilatato et truncatOy linea elevata e umbo- 

 nibus ad marginem ventralem ; transversim valde costatay 

 costis acutis subimbricatis. 

 Hab. China Sea, deep water {A. Adams). 



This is a small pale pink or flesh-coloured species, strongly rib- 

 bed, the ribs being sharp, prominent and imbricated ; the posterior 

 side is dilated and truncate, and the surface of the valves is marked 

 with faint linear radiating lines. 



Crassatella compta, A. Adams. C. testa ovato-trigonaliy 

 subcequilaterali, apicibus antrorsmn curvatisy rufescentiy trans- 

 verse concentrice plicata ; plicis validis, regularibus, subdi- 

 stantibus ; latere antico angustioriy postico latioriy rotundatOy 

 interne purpurascente. 

 Hab. China Sea, deep water {A. Adams). 



This is a small red species, with prominent curved beaks, strongly 

 plicate transversely, and of a purplish pink colour in the interior of 

 the valves. 



Crassatella conctnna, A. Adams. C. testa ovato-transversa, 

 subcequilaterali, epidermide tenui fusca obtectUy utrinque ro- 

 tundata, concentrice plicata, plicis validis regularibus rufo- 

 fusco articulatis ; interstitiis creberrime longitudinaliter stria- 

 tis ; umbonibus acutis confer tis. 

 Hab. China Sea, deep water (A. Adams). 



A small fuscous species, of an ovate form, rounded at both ends, 

 with the transverse plicae strongly produced and prettily articulated 

 with brownish red. 



royal institution of great BRITAIN. 



May 12, 1854.— Sir Henry Holland, Bart., M.D., F.R.S., Vice- 

 President, in the Chair. 



On the common Plan of Animal Forms. By Thomas Huxley, Esq., 



F.R.S. 



The Lecturer commenced by referring to a short essay by Goethe — 

 the last which proceeded from his pen — containing a critical account 

 of a discussion bearing upon the doctrine of the Unity of Organization 

 of Animals, which had then (1830) just taken place in the French 

 Academy. Goethe said that, for him, this controversy was of more 

 importance than the Revolution of July which immediately followed 

 it — a declaration which might almost be regarded as a prophecy ; for 

 while the Charte and those who established it have vanished as 

 though they had never been, the Doctrine of Unity of Organization 



