THE BRITISH FOSSIL BRACHIOPODA. 



357 







Palaeozoic. 



Mesozoic. 



Cainozoic. 



Sub- Families and Geneba. 



a 



3 

 O 



a 



CO 



a 



o 



O 



i 



'5 

 o 



% 

 6 



a 



| 



.1 

 H 





1 



1 



s 

 o 



1 

 ■5 







VII. Family Stbophc 



Into this family several so- 

 termed genera have been 

 placed, but which will re- 

 quire further examination 

 before they can be all finally 

 admitted. 



MENID.E, King, 1846. 



' Orthisina, d'Orb., 1847 



Meekella, White, 1870 



Streptorhynchus, King, 1850 



Derbyia, Waagen, 1884 



Strophomena, Raf., 1820 



Orthoteles, Fischer, 1829 



Strophodonta, Hall, 1850 



Tropidoleptus, Hall, 1857 



Lepttena, Datman, 1828 





— 





— 



— 







P 













| 



















VIII. Family Productid^:, King, 1846. 



f Productus, Sow., 1812 



j Productella, Hall, 1867 



This is a well characterised J Strophalosia, King, 1844 



family. j Aulosteges, Helmersen, 1847... 



1 Chonetes, Fischer, 1837 



L Aulacorhynchus,.Di«»2a» , ,1871 



-j- 





... | ... 



— ■ 





1 









I 



Family— TEREBRATULID/E. 



At p. 329 of his work ' On the Carboniferous Fossils of the Salt Range,' Dr. Waagen 

 says that " In the systematic arrangement of the Mollusca in general, there has in recent 

 times prevailed a tendency to restrict the large generic groups, resolving them 

 into a number of smaller and more sharply defined genera, which should at the same 

 time serve to bring out more clearly the changes the Mollusca have undergone 

 in time, so as to unite under one generic heading those forms which are not very far 

 separated from each other in time. There is no obvious reason why the Brachio- 

 poda should be excluded from the tendency now prevailing among men of science in 

 relation to the Mollusca proper, the less so as the shells of the Brachiopoda require even 

 sharper distinction than do the shells of the Mollusca. Any one who has ever had to deter- 

 mine the shells of the Brachiopoda must know that in certain groups, for instance, in the 

 group of the biplicate Terebratula, it is nearly impossible to determine a species without 

 knowing the formation from which the specimens came ; and, even if this latter fact be 

 known, it requires the utmost carefulness and the observation of the most minute 

 characters to distinguish the different species, and arrive at a satisfactory specific 

 determination of these shells." 



