﻿THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE II. VOL. IV. 



No. IV.— APEIL, 1877. 



OIJIC3-I3^-A.Xi J^I2,TIGIjES. 



I. — What is a Brachiopod ? '■ 

 By Thomas Davidson, F.E.S., F.G.S., V.P.P.S., etc. 

 PAET I. 

 (PLATES VII. AND VIII.2) 

 'E are all aware that it is very often much easier to put a 

 question than to obtain an entirely satisfactory answer, and 

 I am consequently sorry to have to begin my few observations on a 

 very extensive class or group of organisms, by stating that zoologists 

 and comparative anatomists have not yet entirely agreed as to the 

 exact position it should occupy among invertebrate animals. 



The first species belonging to the class were imperfectly and 

 quaintly described and figured by Fabio Columna as far back as 

 1606, and for many years were supposed to be referable to the genus 

 Anomia, one of the Lamellihrandiiata; but as was judiciously observed 

 by Edward Forbes, "A close examination shows that there is no 

 relationship between them, but only a resemblance through formal 

 analogy." It is during the present century that the class itself has 

 been worked out and understood, and this has been achieved after 

 the most lengthened and persevering researches. 



It will not be possible in a short article to enter upon a complete 

 history of the progress made by science up to the present time with 

 respect to the Brachiopoda. Suffice it to say, that many of the most 

 eminent zoologists and palfBontologists have materially contributed 

 to our knowledge of the group, and I have devoted the best portion 

 of my life to its elucidation. We may however observe that, pre- 

 viously to the present century, several naturalists had published notes 

 of some interest upon the Brachiopoda, which have helped to bring 

 the subject under the special notice of the more experienced mala- 

 cologists of our time. In 1675, 1687, and 1688, Martini Lister 

 published figures of a few recognizable species of Brachiopoda, and 

 in particular of Prodiictus giganteus. In 1696 Llhwyd proposed the 

 name Terebratula for several of the shells that had previously been 

 referred to Anomia: he also gave some good figures of several 



1 This memoir is the substance of a lecture delivered by the author to the Brighton 

 and Sussex Natural History Society on the llth of February, 1875, and subsequently 

 published in French with additions and plates in vol. x. of the Annales de la Societe 

 Malacologique de Belgique for ] 876. 



2 Plates IX. and X. will accompany Part II. 



DECADE II. VOL. IV. — NO. IV. 10 



