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SUPPLEMENT TO THE BRITISH 



specimen may be seen in the York Museum. This name is allowed by Dr. Schloenbach 

 to be a synonym of the species under description. 



Terebratulina Defrancei may or may not be a full-grown condition of T. striata. Some 1 

 Palaeontologists take one view, some the other. It will, therefore, be as well to retain 

 the name Defrancei as, at least, a varietal designation. A great many so-termed species 

 have been made out of variations in age and shape of this far-spread species, as is 

 likewise the case Avith T. caput-serpentis ; and it seems difficult to determine whether in 

 reality T. striata has been found lower down than the Chalk-marl. Mr. Meyer is of 

 opinion that the Terebratulina we have figured from the Upper Greensand may very 

 probably constitute a well-marked variety or species. We will, therefore, keep them 

 separate, as well as the shell (fig. 26) from the Speeton Clay of Knapton in Yorkshire. 



D'Orbigny's Terebratulina Dutempleana and Schloenbach's T. Seebachii look very like 

 young shells of T. striata. 



It may likewise be a question for further consideration whether the Terebratulina 

 (figs. 27 and 28) from the Upper Greensand of Warminster should constitute a distinct 

 variety. 



25. Terebratulina striata, var. Defrancei. Sup., PI. II, fig. 13. 



I am acquainted with the anterior half of a single specimen, which, if complete, 

 would have measured about one inch and seven lines in length by one inch two lines in 

 breadth. This fragment was described and figured by Mr. R. Tate in the ' Quart. Journ. 

 Geological Society,' vol. xxi, p. 42, pi. iv, fig. 4, 1864, from a specimen found in the 

 flinty flag (Upper Chalk) of Kilcorig, Lisburn, Ireland. In well-preserved examples 

 of T. Defrancei the dorsal valve is comparatively very much more convex and laterally 

 compressed than is the case with T. striata, and there exists also a wide, well-defined 

 longitudinal depression near the front. The striae, which cover the surface of the valves, 

 are so exceedingly numerous and fine that they can be hardly seen without the aid of a 

 lens. The front is also straight and does not show any trace of that indentation so 

 commonly present in specimens of true T. striata. 



26. Terebratulina striata, var. elongata, Dav. 



Terebratulina striata, Meyer. Geol. Mag., vol. i, p. 253, pi. xii, figs. 26, 27, 1864. 



This species or variety (?), according to Mr. Meyer's figures, differs from the Chalk 

 specimens in being more regularly elongated in all stages of its growth and in not being 

 indented in front. This last feature loses, however, somewhat of its importance from 



