CHAP. VIII. CALYPTR^A. 233 



will arrange themselves under one or other of these 

 types. Without enlarging further upon these analogies, 

 we may briefly state that they are in perfect uniformity 

 with that principle of variation which runs through 

 the whole of the animal kingdom. It was long ago 

 announced by one of the most philosophic naturalists 

 of the age, that when Nature^ so to speak, is about 

 entering a large assemblage, she gives, as it were, in 

 the onset, a sketch of the five leading forms she 

 intends to adhere to, although under innumerable mo- 

 difications. Thus, in the class of Acrita, as MacLeay 

 observes, she typifies the five great classes of animals ; 

 and thus again, in the very first group of the spiral 

 univalves, she presents us with indications of the five 

 great families of the phytophagous and zoophagous 

 Gasteropoda, all concentrated in the limits of a single 

 genus. 



(216.) The station of Lamarck's genus Calyp- 

 TR^A is fully determined by the structure of his Sto- 

 matella duplkata, since both form an obvious passage 

 to the Trochidce, by showing the fi.rst developement of 

 a central pillar. Lamarck's observations upon this 

 interesting group, which contains many natural sub- 

 genera, appear to us characteristic of that accurate per- 

 ception, almost intuitive, of natural affinities and 

 relations which characterised all his writings before his 

 unfortunate blindness, — a rare talent of discrimination, 

 which, as it has been justly observed by others, places 

 him, in this respect, far above even the author of the 

 Regne Animal. Although he had not the advantage 

 of being acquainted with the animal, made known to 

 us by the unpublished drawings of Guilding* (of 

 which the annexed cut is a copy, fig. 42.), he con- 

 sidered this genus, not related (by affinity) to Fatella, 

 but that its incipient spire and pillar indicated a struc- 

 ture approaching to that of Trochus. He erred, appa- 

 rently, in carrying this theory too far^ by supposing 



* The typical form is probably C. Chinensis, the species here figured. 



