SUCCESSION AND STANDING OF ANIMALS. 163 



specting the relative rank of their living representatives 

 than among Echinodcrms. Every zoologist acknowledges 

 the inferiority of the Bryozoa and the Brachiopods 1 when 

 compared with the Lamellibranchiata ; and among these, 

 the inferiority of the Monomyaria in comparison with the 

 Dimyaria would hardly be denied. Now, if any fact is 

 well established in Palaeontology, it is the earlier appear- 

 ance and prevalence of Bryozoa and Brachiopods in the 

 oldest geological formations, and their extraordinary 

 development for a long succession of ages, until Lamel- 

 libranchiata assume the ascendancy, which they maintain 

 to the fullest extent at present. A closer comparison of 

 the different families of these orders might further show 

 how close this correspondence is through all ages. 



Of Gasteropoda I have nothing special to say, as every 

 palaeontologist is aware how imperfectly their remains 

 have been investigated, in comparison with what has been 

 done for the fossils of other classes. Yet the Pulmonata 

 are known to be of more recent origin than the Bran- 

 chifera, and among these the Siphonostomata to have 

 appeared later than the Holostoma, and this already 

 exhibits a general coincidence between their succession in 

 time and their respective rank. 



Our present knowledge of the anatomy of the Nautilus, 

 for which science is indebted to the skill of Owen, 2 must 



1 OBBIGNY, (A. D',) Bryozoires, Anatomy of the Terebratula, 1853, 



Ann. Sc. Nat., 3e ser. 1851, vol. 16, 4to. fig. (Palseont. Soc.) Bucn, (L. 



p. 292. BUSK, (G.,) Catalogue of v.,) Ueber Terebrateln, q. a., p. 146. 



marine Polyzoa in the collection of DAVIDSON, (Tn.,) Monogr. etc., q. 



the British Museum ; London, 1854. a., p. 146. POLI (XAV.,) Testacea 



CUVIER, (G.,) Memoire sur 1'animal utriusque Sicilue, eorumque Historia 



de la Lingule, Ann. Mus. I, p. 69, fig. et Anatornia ; Parma3, 1791-93, 2 vols. 



VOGT, (C.,) Anatomic der Lingula fol. fig., continued by Delle Chiaje. 

 anatina, N. Mem. Soc. Ilelv. 1843, 2 OWEN, (R.) Memoir on the Pearly 



VII, 4to. fig. OWEN, (R.,) On the Nautilus ; London, 1832, 4to. fig. 



Anatomy of the Brachiopoda, Trans. VALENCIENNES, (A.,) Nouvelles Re- 



Zool. Soc., I, 4to. p. 145, fig. On the cherches anatomiques sur le Nautile. 



M 2 



