CHAPTER XYII 



KECENT BKACHIOPODA 



INTRODUCTION — SHELL — BODY — DIGESTIVE SYSTEM — BODY 

 CAVITY — CIRCULATORY SYSTEM — EXCRETORY ORGANS — 



MUSCLES NERVOUS SYSTEM — REPRODUCTIVE SYSTEM — 



EMBRYOLOGY — HABITS — DISTRIBUTION — CLASSIFICATION 



Introduction 



The group Brachiopoda owes its chief interest to the im- 

 mense variety and great antiquity of its fossil forms. Whereas 

 at the present time the number of extant species amounts to but 

 about 120, Davidson in his admirable monograph ^ on the Brit- 

 ish Fossil Brachiopoda has enumerated close upon 1000 fossil 

 species, found within the limits of the United Kingdom alone. 



The amount of interest that the group in question has 

 excited amongst naturalists is evinced by the invaluable Biblio- 

 graphy of Brachiopoda, prepared by the same author and his 

 friend W. H. Dalton.^ This monument of patient research 

 contains over 160 quarto pages, each with the titles of from 

 eighteen to twenty separate papers dealing with Brachiopods, 

 published between the years 1606 and 1885. 



Probably the first reference to Brachiopods in zoological 

 literature is to be found in a work entitled Aquatilium et 

 Terrestrium aliquot Animalium^ published in the year 1606 by 

 Prince Fabio Colonna at Rome. This work contains the first 

 description of a Brachiopod under the name of Concha di'phya. 

 In a second edition, which is not so rare in our libraries as the 



1 "A Monograph of the British Fossil Brachiopoda," Palaeontographical 

 Society, London, vols. i.-v. 1851-84. 



2 Ibid, vol. vi. 1886. 



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