fHE BRACHIOPODA. 13 



5. TEREBRATULA BUCKMANI, Davidson. 



1851. TEREBRATULA BUCKMANI, Davidson. British Brach. 

 Palccont. Soc., plate vii., figures 15-16. 



The specimens from this district are generally a very slight 

 variation of the Cotteswold forms, that is, they are thinner and 

 have a rather flattish dorsal valve. Tereb. Buckmani, however, is 

 rather variable, and gradually passes into those varieties which 

 have been separated by Mr. Walker under the name of variety 

 T. Buckmcinima. All these occur together in a peculiarly irony 

 stone (zone of Stephan. Humphriesianum) near Half-way House, 

 Compton. The forms which agree with the true Tereb. Buckmani 

 are rather rare, but the variety Ter. Buckmaniana is much 

 commoner. 



Localities. Near Half-way House and at Oborne (Dorset), 

 also near Cheltenham (Gloucestershire). 



Obs. Some authors have placed Tereb. Buckmani as a synonym 

 of Tereb. ventricosa Hartmann, but Mr. Davidson observes 

 " Mr. Deslongschamps adds to his description of this species (T. 

 ventricosa J a long synonomy, among which he places the shell to 

 which I gave the name of Tereb. Buckmani, but I cannot admit 

 this identification when I compare it with German and French 

 examples and figures of Hartrnann's or Zieteu's shell.* 



5a. TEREBRATULA BUCKMANI, variety BUCKMANIANA, 



Walker. 



1878. TEREB. BUCKMANI, VAR. BUCKMANIANA, Davidson, British 

 Brachiopoda Palseont. Soc., plate xix., 

 figures, 14-17. 



Along with Ter el. Buckmani occur numerous varieties, such as 

 are well represented by Mr. Davidson in the above reference. 

 These forms differ chiefly from T. Buckmani in being more or 

 less distinctly biplicated and much thicker, or else broader and 



* Davidson, British Fossil Brachiopoda, PaLeont. Soc. 1876, page 127, 

 vol. xxx. 



