260 PROCEEDINGS OF THE 



III. — On the Occurrence of the genus Pentremites (Say.) in the 

 Carboniferous Limestone Series of the East of Scotland. By 

 Mr. R. Etheridge, Jun., F.G.S., Pres. Boy. Physical Soc, 

 Edinburgh. Plate V., figs. 7-12. 



In the Geological Magazine for March, 1878,* I called atten- 

 tion to the probable occurrence of the genus Pentremites in Scot- 

 tish carboniferous rocks — an opinion based on the finding of a 

 small and separate ambulacrum by Mr. James Bennie, which 

 clearly belonged to some member of the Blastoidea and distinct 

 from the curious little Astrocrinites Benniei (mini). 



Shortly after this announcement, thanks to Mr. Bennie's per- 

 severing efforts, a few crushed specimens of a small Pentremite 

 were actually found at Kidlaw in Haddingtonshire. 



Unfortunately, as is often the case in specimens of great and 

 unusual interest, these precious examples were either so frag- 

 mentary or greatly crushed, that I was afraid little beyond 

 satisfactorily proving the identity of the genus could be made of 

 them. However, further examination gave a more hopeful view 

 of the case, and believing that so important a discovery should not 

 remain unchronicled, I beg to offer the following description of the 

 fossils. 



My thanks are due to Prof. A. Geikie, LL.D., F.R.S., etc., for 

 permission to make use of the specimens for descriptions, and to 

 Mr. James Bennie for the cordial manner in which he endeavoured 

 to obtain further and better material. 



One of the two entire specimens is crushed from above down- 

 wards. On one side it exhibits traces of the ambulacra, and 

 the position of the radial and oral plates, but beyond these 

 points the matrix hides everything from view. On the other side 

 the plates of the calyx have become crushed together, and all that 

 is distinct is the ornamentation of the surface, which will be 

 described further on. 



The second and best specimen (Pi. V., fig. 7) has been crushed 

 from side to side, but in such a manner as to leave the leading- 

 features of the fossil apparent, especially on one side. The supple- 

 mentary basal plates first detected in the calyx of Pentremites by 

 Mr. S. S. Lyont are not visible at all, and the basals themselves are 



:: Vol. v., dec. 2, p. 118. 



t D. D. Owen's Third Report Geol. Survey of Kentucky, 1856-57, p. 469. 



