274 Royal Institution. 



aperturd pyriformi, intus striatd, columelld lavi, nitidiusculd, cy- 

 lindraced, canali recurvo, aperto. 



Long. 17^, lat. 9| lin. 



Patria ? 



(Exstat in museo Gniner.) 



The form of this shell differs so much from all those known to 

 me, that I find it impossible to compare it with any of them ; its 

 only resemblance is to a product of art— r-to the roof of a Chinese 

 pagoda, and for this similarity's sake I have named it Pyrula idoleum. 

 Starting from the supposition that in former times men took the 

 productions of nature which surrounded them as models for their 

 works of art, the peculiar form of this shell has suggested to me the 

 conjecture that it originates from China ; in all probability we shall 

 yet obtain from this country many strange forms, as for example the 

 Pyrula Mawece, which is brought from the Chinese Sea. 



Anomia naviformis, Jonas. An. testd transversim elongatd, an- 

 gustd, tenuiypellucidd, marginibus dor sail et ventrali parallelis, rec- 

 tis, lateralibus hrevibus, rotundatis ; valvd majore cened, valde con- 

 cavd, minore albd, fragilissimd, concaviusculd ; foramine ovato, 

 integro. 

 Long. 16, lat. 4 lin. 

 Patriam ignoro. 



ITiis Anomia may perhaps be an aberrant form of the A. cBnigma- 

 tica, with which it has great resemblance in the texture of the shell, 

 position of the umbones and form of the foramen ; but I do not dare 

 to assert this, and therefore I describe it as a peculiar species till 

 intermediate species are found, forming the links of a chain, of which 

 the above two are the terminating ones. 



Mr. Tomes exhibited to the Meeting a specimen of the Bimacu- 

 lated Duck, Anas glocitans, which he had obtained in Leadenhall- 

 market ; the specimen is a female, and agrees in size and plumage 

 with that in the Society's collection. 



ROYAL INSTITUTION. 



March 5, 1847. — " On the Successive Phases of Geological Sci- 

 ence." By Prof. Ansted. 



The lecturer stated that he proposed to give something of a psy- 

 chological view of geological history, — tracing the successive ideas 

 that seem to have prevailed and to have chiefly contributed towards 

 the advancement of the science, — and pointing out how far these 

 ideas involved truth, and how far errors of exaggeration, although 

 they were useful as suggesting new views and observations. After 

 passing rapidly under review the philosophy of the ancients and the 

 cosmogony of the middle ages — which latter he described as without 

 the true aspect of philosophic investigation — the lecturer referred to 

 the discoveries of Werner as being the first which distinctly created 

 geological science. He stated that these discoveries induced three 

 important assumptions : — first, that the whole crust of the earth had 



