THE BRITISH FOSSIL BRACHIOPODA. 345 



Very few genera had been proposed for the Brachiopoda during the 17th and 18th 

 centuries ; the species then known being placed chiefly under Anomia, Terebratula, and 

 Lingula, and no really serious attempt at classification having been attempted. 



The progress effected in our knowledge of the fossil forms and their classification 

 has been immense, especially during the last forty years, as testified by the great number 

 of large works and papers in which both recent and fossil Brachiopoda have been 

 described and beautifully illustrated. 



For some years subsequent to 1800 the number of families and genera into which 

 the Brachipoda were divided continued very small ; and in the General Introduction to 

 Volume I of this Monograph will be found an account of what was known upon the 

 subject up to 1853. 



The absolute necessity of separating the Rhgnchonella from the Terebratula had been 

 foreseen even by early naturalists. Morton in 1712 seems to have been among the first 

 to arrange his Terebratula into two distinct divisions ; in the first he placed those species 

 with a truncated beak, and in the second those in which the beak is acute and entire; 

 these divisions corresponding — the first to the genus Terebratula, the second to 

 that of Rhgnchonella of modern authors. Davila in 1767 likewise alluded 

 to the distinction between these shells, and noticed the difference in their apophy- 

 sary system ; but it is to Gotthelf Fischer de Waldheim that the credit is due of 

 having introduced the generic name of Rhgnchonella in a paper entitled " Notice des 

 Fossiles du Gouvernement de Moscou, servant de programme pour inviterles membres de 

 la Societe Imperiale des Naturalistes a la Seance pnblique du 26 octobre a Moscou 

 1809 " l his type being the Rhgnchonella Loxia, a shell very abundant in the Jurassic 

 rocks of the neighbourhood of Moscow. He also gave the name of Rhgnchonella 

 " canard" to another species, figured by Bruguiere in Tab. 245, fig. 6, of the ' Encyclop. 

 methodique,' and Rhgnchonella " aigle," ' Ency.,' Tab. 246, fig. 1, which last is a Jurassic 

 or Cretaceous Rhgnchonella. 



This was a valuable addition to our knowledge ; but this important and long-lived 

 genus was quite ignored for many years subsequent to its publication ; geologists and 



The whole is automatic, being worked by water-power taken from an ordinary tap. The substance to be 

 cut is embedded in paraffin of a particular melting-point, which must be varied with the temperature of 

 the laboratory at the time, a matter easily arranged. The subject, supported by the paraffin, is moved 

 very rapidly backwards and forwards against the horizontal knife, and a series of sections of any desired 

 fineness are thus cut. Each fresh section formed strikes the edge of the section formed at the preceding 

 blow against the knife and adheres to it. Thus, a continuous riband of sections emerges from the 

 machine with considerable rapidity, and it is only necessary to cut off lengths from it and receive them on 

 slides, the great advantage being that they maintain their order exactly, and that no fragment is lost. It 

 is possible to cut sections similarly in a riband by hand ; but the work is done much more uniformly, and 

 rapidly, and certainly by the automatic machine prepared by the Cambridge Instrumental Company. The 

 paraffin is removed by warmth and benzine, and the sections are then mounted in Canada balsam." 



1 This paper seems to be very scarce. I had the greatest trouble in obtaining a copy of it. One 

 maybe seen, however, in the Library of the Linusean Society of London. 



