68 INVERTEBRATE PALAEONTOLOGY 



fewer difficulties appear when classification is attempted 

 on a broader basis. The restriction of evidence to 

 durable structures, whose modifications often have little 

 connexion with those of more "vital" organs, cannot 

 but impair the quality of systematic grouping. More- 

 over, it compels adoption of different principles from 

 those employed in Biology. Sections of the Echinoidea 

 based on characters of pedicellariae, of Gastropoda on 

 the distribution of radular teeth, or of Cephalopoda on 

 the number of branchiae, C3.n never be recognized by 

 Palaeontologists by direct observation, although they 

 may be far more sound than the makeshift schemes 

 that have to be erected. When recent representatives 

 of fossil groups exist, it is often possible to apply 

 zoological classification provisionally, but the inclusion 

 of many forms in " malacological " divisions must always 

 be tentative. The normal trend of zoological research 

 seems to lead its devotees to overlook the shells or 

 skeletons of Invertebrates in their eagerness to study the 

 soft tissues. This regrettable tendency is less marked 

 in the case of Vertebrates, but for many Invertebrate 

 groups analysis of the hard-parts of living forms has 

 been left to Palaeontologists, who sought in vain for 

 the information they needed in the records of biological 

 literature. 



There is a constant temptation, by no means restricted 

 to Palaeontologists, to regard the application of a name 

 to every specimen as a sufficient end, after whose attain- 

 ment the fossil is " done with " except for storage or 

 display. Necessary though names must be, they are 

 not attributes of the organisms, but merely conventional 

 terms designed to facilitate reference. A fossil con- 

 tinues to display its morphological peculiarities whether 

 named rightly, wrongly, or not at all; appreciation of 

 its natural qualities, absolute and relative, is far more 



