161 



perhaps Sp. Crista Hisinger (PI. 2, Fig. 9 h). Lastly, two 

 small pieces of matrix (marked E) have a Spirifer similar to the 

 coarsely- ribbed form just mentioned, and what I believe to be 

 several fragmentary casts of a small Strophomena (PI. 2, 

 Fig. 11). 



On opening these remarks, I alluded to a TentacuUtes. 

 It consists simply of impressions of the exterior, apparently 

 representing a simple ridged form (PI. 2, Fig. 12). 



A few words may now be said as to the probable age of the 

 blocks, or at least some of those forming the Table Cape Con- 

 glomerate. In British rocks, Pentamerus first makes its 

 appearance in the Lower Llandovery, and ascends to the 

 Aymestry Limestone. The genus is again met with in the 

 Middle Devonian. It is, however, particularly characteristic 

 of the Upper Llandovery beds, or May Hill Sandstone. In 

 America it occupies very much the same stratigraphical 

 position, and is particularly characteristic of the Niagara 

 Group. The latter forms the base of the Upper Silurian, 

 just as the May Hill Sandstone does in Britain. The other 

 determinations, being open to criticism, need not have too much 

 stress laid upon them. It may, however, be pointed out that 

 both Spirifera elevata and S. plicatella are Upper Silurian 

 forms, whilst Orthis hiforata has a more extended range. 



Next to the Pentamerus in importance are the impressions 

 of the TentacuUtes. This genus of Pteropod Mollusca ranges 

 from the Caradoc upwards, but attains its maximum develop- 

 ment in the Upper Silurian, although it does extend into the 

 Devonian. 



On the whole, it may be said, with a fair amount of proba- 

 bility, that at least some of the Table Cape boulders are of 

 Upper Silurian age, the stratigraphical sub-division of the 

 May Hill Sandstone putting in a very strong claim for recog- 

 nition. 



I have to express my hearty thanks to my friend, Mr. T. 

 Davidson, F.E.S., for his assistance in the provisional deter- 

 mination of the foregoing species of Brachiopoda. Mr. 

 Davidson's assistance is always the more valuable from the 

 hearty manner in which it is rendered. 



DESCRIPTION OF THE FIGURES. 

 Plate I. 



Fig. L Conocephalites Stephensi. B. Etli., Junr. The 

 glabella and remains of one fixed cheek ; the former shows 

 the four pit-like furrows on each side, and the central in- 

 dentation in the front ; across the latter is visible the ocular 

 ridge, or eye-line. 



Fig, 2. Another example of the same, with lying on it a 

 free cheek and remains of the eye. 



Fig. 3. Another free cheek, probably belonging to this 



