ANKIVEESARY ADDRESS OP THE PRESIDENT. 11 



lemnitidce. The most commonly preserved portion in the fossil state 

 is the posterior or caudal portion of the guard or sheath, which 

 was originally considered as the Belemnite ^ar excellence, until it 

 was subsequently discovered that as this guard extended forwards 

 it formed a conical cavity filled with a shell of similar form, gradu- 

 ally expanding forwards, divided by many shelly plates, and pierced 

 by a small pipe or siphuncle near one edge. This is called the 

 phragmocone, and is rarely found complete ; when such, however, is 

 the case, it is covered by a thin conical shell distinct from the sub- 

 stance of the guard, and called " conotheca " by Huxley. With 

 regard to the guard itself Prof. Phillips observes, that it is neces- 

 sary that it should be carefully observed in three distinct aspects, 

 viz. the dorsal and ventral faces, as well as along the axis or 

 apical line. Although specimens are extremely rare in which the 

 2)hragmocone and guard are found together completely, yet in spe- 

 cimens from the Lias of Lyme Regis and of Yorkshire the structure 

 of the phragmocone in relation to the guard has been sufficiently 

 ascertained to justify a restoration of the whole shell. 



The author then proceeds to describe the classification of the 

 Belemnitidae, but this chapter is unfinished ; and no plates or 

 illustrations, except woodcuts, are given in this portion of the mono- 

 graph. 



The next paper is the " Monograph of the Fossil Eeptilia of the 

 Liassic formation," by Prof. Owen : part first, Sauropterygia. The 

 work commences with a detailed account of Plesiosaurus doliclio- 

 cleirus, followed by P. lioyyialospondylus, P. rostratus (Owen), and P. 

 rugosus (Owen), and is accompanied by 16 plates. The merit of 

 these osteological papers of Prof. Owen is so well known that it is 

 unnecessary for me to say more than that the detailed description 

 appears to exhaust whatever can be said respecting these extinct rep- 

 tiles, their mode of entombment, and the resulting positions in which 

 they have been found. 



Although I do not, as a rule, purpose alluding to the papers which 

 have been read at our evening meetings, yet there are some which 

 appear to be of sufficient interest to justify my noticing them on the 

 present occasion. The organic structui-e of the Eozobn Canadense 

 to which I alluded last year, has been called in question by 

 Prof. W. King and Dr. Eowney in a paper recently read before the 

 Society. Having examined numerous specimens of Eozoonal Ser- 

 pentine from various localities, the authors consider that the ap- 

 pearances which Dr. Carpenter and others have pronounced to be 

 organic, and closely to resemble foraminiferal structure, are purely 

 of mineralogical origin. They consider the '' skeleton " to be iden- 

 tical with the calcareous matrix of certain minerals, as Chondrodite, 

 Pargasite, &c. The " proper wall " of the chambers is not an in- 

 dependent structure, in their opinion, bat only the surface -portion of 

 the granules of chrysotile crystallized into an asbestiform layer. 

 The dendritic and other forms which were described as repre- 

 senting the " canal system," are considered by them to be tufts of 

 metaxite, or some allied variety of chrysotile ; and these and other 



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