BRACHIOPODA. 6 



specimens of it at Uddevalla, in the course of a short 

 exploration of the raised sea-bed in that remarkably in- 

 teresting place. T. septata (or septigera), as regards the 

 frequency of its occurrence, may be placed in the same 

 category. The examination of fossiliferous strata is 

 attended with no risk, and the specimens are procured 

 without much difficulty; but I much doubt if we should 

 not find in a modern sea-bed, of the same extent and 

 having similar conditions, a collection of Brachiopoda 

 fully equal in number and variety to those contained in 

 any one Palseozoic, Mesozoic, or Cainozoic formation. 

 So many recent species have been made out of solitary 

 or a very few specimens, that it is evident much remains 

 to be known of this curious group as it at present exists. 

 Being individually numerous, and comparatively low in 

 the scale of organization, the tendency to variation is 

 of course great. An examination of nearly all the types 

 of recent species induces me to suggest the necessity of 

 a complete revision of these so-called species. 



This group has been for more than half a century a 

 favourite study of naturalists. Pallas, Cuvier, De Blain- 

 ville, Owen, Quenstedt, Deshayes, Yogt, Forbes, Hux- 

 ley, M. J. Muller, Schmidt, Deslongchamps, Carpenter, 

 Barrett, Woodward, Gratiolet, Hancock, F. Muller, 

 Macdonald, Lacaze-Duthiers,and Shaler have at different 

 periods contributed a vast store of information as to the 

 structure of recent Brachiopoda; while De Koninck, 

 D'Orbigny, M'Coy, King, Davidson, Suess, and other 

 able palaeontologists have made us acquainted with the 

 fossil forms. Mr. Reeve has also rendered some good 

 service in respect of the synonymy and geographical dis- 

 tribution of existing species. Mr. Hancock's valuable 

 paper " on the Organization of the Brachiopoda " will 

 be found in the c Philosophical Transactions' for 1858. 



b 2 



