Mr. T. Davidson on Recent Terebratulse. 25 



was published " A Sketch of a Classification of recent Brachio- 

 poda based upon Internal Organization/' the result of investiga- 

 tions undeilaken along with my distinguished friend Mr. S. P. 

 Woodward of the British Museum. 



For many years previous to that period (since 1835 or 1836) 

 my serious attention had been given to the Brachiopoda in ge- 

 neral, and at a later period more particularly to the fossil forms 

 which had to be elaborated for the monograph published by the 

 Palseontographical Society, From 1846 to 1852 some portion 

 of my time was directed, under favourable circumstances, to the 

 recent forms and their organization, from having duly estimated 

 the great advantages to be derived from an attentive study of 

 the animal and shell of the living forms, as well as from having 

 noticed that a considerable number of species had been assem- 

 bled, figured, and described in Parts vi. & vii. of G. B. Sowerby's 

 * Thesaurus Conchyliorum' (for 1846). It appeared to me there- 

 fore that some endeavour should be made to arrange those spe- 

 cies according to their internal organization ; and consequently, 

 in May 1852, the 'Sketch' above mentioned, with its many 

 imperfections, was published ; but in so doing I distinctly inti- 

 mated (p. 362) that it could not be expected that this first at- 

 tempt to classify the recent species of living Tei-ebratula should 

 be entirely successful, but that such a classification had become 

 not only desirable, but necessary, and that no good would be 

 accomplished by delaying its publication. It is therefore a 

 source of some gratification to perceive that the ' Sketch of a 

 (classification ' has been very generally adopted in principle, and 

 with but few modifications in detail, by those naturalists who, 

 subsequent to 1852, have devoted their attention to the subject, 

 and especially by my learned friends Prof. Suess and Mr. L. 

 Reeve, who have recently laid before the public their very valu- 

 able detailed revisions of the history, synonymy, and geographical 

 distribution of the recent Brachiopoda. 



Before referring to the publications of the last-named natu- 

 ralists, which will form the chief purpose of the present commu- 

 nication, let us cast a rapid glance at what has been done since 

 1852 with reference to the recent species, leaving aside for the 

 present the fossil ones, although no really comprehensive plan 

 can be carried out without due regard to, as well as a thorough 

 knowledge of, the fossil or extinct genera and species. 



One of the fii'st objects, and indeed the most important of 

 all, was to study the aniuial ; and I am truly happy in being 

 able to assert that this ])ortion of the work has been consider- 

 ably and very successfully elaborated, during the last ten years, 

 by several anatomists of high celebrity. In ] 853, Prof. Owen 

 published his views and important observations upon the ana- 



