THE BRITISH FOSSIL BRACHIOPODA. 



355 







Palaeozoic. 



Mesozoic. 



Cainozoic. 



Sub-Families and Gbneba. 



.3 

 S 



o 



a 



a 



w 



c 



'5 



c 

 C 



3 



£ 



'a 



rg 

 6 



a 



1 

 1^ 



H 



« 



1 



o 







III. Family Spibifeeacea (continued). 



f Anazyga, Bav., 1882 



.wojamty 









— 























Hindella, Mav., 1882 



6. Sub-family KONINCKINID.E. « 



r Anoplotheca, Sandberger, 1857 



Koninckina, Suess, 1853 



Koninckella, Munier- Chalmas, 

 1880 





? Davidsonia, Bouchard, 1849 





IV. Family Rhtnchonellinid^;. 

 1. Sub-family Rhynchonel- f 



tjsm. 1 Rhynchonella, Fischer, 1809... 

 D'Orbigny has proposed a genus ? Terebratuloidea, Waagen, 



Acantholhyris for R. spinosa ; \ 1883 



Bayle a genus JJncinulus for J, RhvnchoDora. Kina. 1856 

























... 





such shells as Rh. sub- Wilsoni; 

 but I question the necessity 

 of removing them from the 

 genus Rhynchonella. 



2. Sub-family Camaeophoeike. - 



Eatonia, Mall, 1857 









Dimerella, Zittel, 1870 



Atretia, Jeffreys, 1876 







f Pentamerus, Soto., 1813 



1 Pentamerella, Mall, 1839 



3. Subfamily Pentamebinje. \ Stricklandinia, Billings, 1863 



1 ? Amphigenia, Mall, 1869 



1, ? Camarella, Billings, 1859 ... 









""^ 





Generio position and family 

 still undetermined. 



r ? Leiorhynchus, Mall, 1860... 

 . ? Eichwaldia, Billings, 1858 > 



inadvertently omitted to refer to its remarkable shell-structure described and figured by Prof. Lindstrom 

 at p. 25 of his and Angelin's ' Fragmenta Silurica,' 1880. Prof. Lindstrom remarks that the shell of the 

 ventral valve consists of two layers, of which the innermost only occupies the bare space at the beak ; 

 and that the external layer is perforated by minute tubules running obliquely inwards and downwards, and 

 continued as little furrows, which ornament the surface of the shell in a quincuncial manner. Also that 

 other (horizontal) tubules perforate the test from the inferior part ; and that the beak of the ventral valve 

 is always bare as if by the removal of the external layer. Prof. Lindstrom accompanies his description 

 with several carefully drawn illustrations. 



Since the publication of Prof. Lindstrom's description Mr. John Young has also carefully investigated 

 the shell-structure of Eichwaldia Capewelli, being at the time unacquainted with what Prof. Lindstrom 

 had done in the matter. He writes me, " My examination of this beautiful and interesting shell has led 

 me to recognise three distinct layers in its structure : first, the outer hexagonal layer, in which the walls 

 are thin at the surface but thicker at their base, and cover a layer of minute polygonal cells that are 

 bounded by thin walls. These polygonal cells form the second layer inwards, and are not seen on the 

 surface except when the outer cell-layer has been eroded or not well developed. A certain number of these 

 cells rise above the bottom of the larger cells, and enter the outer cell-walls. In eroded and polished 



47 



