42 INTRODUCTION. 



Linnaeus in 1758. The term Anomia was, however, afterwards appUed to a small group 

 of Lamellibranchiate shells, distinct from that intended by the original denominator. 



In 1712, Morton had perceived the necessity of separating the plaited Terebratulae 

 from the smooth ones, but did not propose any distinct generic appellation;^ and for 

 several years after Columna's first descriptions, but little advance was made towards classi- 

 fication, the few known species having been allowed to remain confounded among the 

 other shell-fish. 



Cuvier, with his acute powers of perception, after having examined the animal of 

 Lingula^ as well as the figm-es of the so-called Patella Anomala of Miiller,^ Criopus 

 of Pallas,* and excellent illustrations of Ter. caput-serpentis by Griindler,^ proposed 

 to create for those animals a distinct class among the Mollusca, to which Dumeril applied 

 the name of Brachiopoda ; so that the History of the Order may with truth be said 

 almost to date from the commencement of the present century ; and when we look back 

 to all that has been achieved since that short period, we may fairly hope that by the 

 expiration of the present century, the history of the class may have nearly attained its 

 fullest development. At the time of Cuvier's first researches, but very few species were 

 discovered, still these had been subdivided into several excellent genera, because the 

 differences existing between the Terebratida, Lingulce, and Cranice {Orhiculce), had not 

 escaped the scrutiny of early investigators. 



The vast impulse given to geological researches since the year 1800, rapidly filled 

 the collectors' cabinets with a rich harvest of new and undescribed forms, many 

 of which, by presenting marked difierences from those already known, tempted 

 Palgeontologists to augment the number of genera, from its having been found necessary 

 to separate that which is fundamentally/ different, as toell as to unite that lohich is 

 really similar-^ nor is it surprising to find in such attempts, at times conducted by 

 inexperienced hands, that numerous errors should have taken root, which time and sub- 



^ Nat. Hist, of Northamptonshire. 



- Memoire sur rAnatomie de la Lingule, 'Mem. du Mus.,' vol. i, 1802. ^ Zoologia Danica, 1/81. 



* Test. Sicil., 1792. ^ Naturforscher, vol. i, 2d part, p. 86, tab. iii, figs. 1—6, 1/74. 



^ This expression is forcibly made use of by Professor M. Edwards and Jules Haime, in their excellent 

 work on * British Fossil Corals.' The confusion that has existed, and still exists, is chiefly caused by the value 

 of the terms Family, Genus, sind Species, being by many authors viewed in a different sense; thus the Genera 

 of some are the equivalents of the Families of others, so that a continual controversy naturally arises. The 

 excellent observations on this point, published by Mr. Strickland, in p. 217 of his report, before the 

 British Association for 1844, should be duly weighed and considered: he observes that, "all groups of the 

 same rank are supposed in theory to possess characters of the same value or amount of importance, and the 

 object of the naturalist should be, to bring them as nearly as possible to this state of equality. It must, 

 indeed, be admitted, that no certain test seems to have been discovered for weighing the value of Zoological 

 characters. The importance of the same characters manifestly varies in different departments of nature, 

 and must therefore be estimated by moral rather than demonstrative evidence. The real test of the value 

 of a structural character ought to be its influence on the economy of the living animal ; but here we too 

 often have to lament our ignorance, or our false inductions, and in many cases we are wholly unable to 



