Mr. T. Stock on Kammplatten. 255 



Horizon. Carboniferous Limestone series. 

 Locality. Burgh Lee, near Edinburgh. 

 In my own collection. 



It was known from the specimens described by Prof. Fritsch 

 that the Bohemian Kammplatten were concave on one surface 

 and convex on the opposite, corresponding with similar con- 

 cavities and convexities on the next apposed plates of the series. 

 The British specimens are constructed on the same plan. Some 

 of them, however, give evidence of the existence of special 

 provisions by which the plates were more closely united with 

 each other. These articulatory specializations are not veiy 

 strongly developed in all of the specimens ; yet they amount in 

 some to a considerable degree of complexity of type. On 

 several of tiiem (Nos. 2, 6, 7, and 8) there are minute punc- 

 tures or short transverse scratches occurring with uniformity 

 of position along the exposed surfaces of the lamellce. These 

 possibly fitted into corresponding prominences on the concave 

 areas of the lamellae of the succeeding plates, though I have 

 not been able to verify this by observation, as nearly all the 

 plates that I have seen have been presented with their convex 

 sides upon the slabs. On the handle, however, of the plate 

 described as No. 8 in this communication (PI. VIIL fig. 3 a) 

 there are strige terminating at about the centre in denticular 

 prominences, which probably fitted into shallow excavations 

 on the concave area of the handle next in the series. Again, 

 in the same specimen, the two pits near the end of the handle 

 and the boss-like termination of the handle itself probably 

 fitted into elevations and a depression on corresponding ]jarts 

 of the next plate. In this specimen, therefore, there is a iiigh 

 degree of articulatory specialization. In No. 7 (PI. Vlil. 

 fig. 2 a) it is of a more simple character, but very distinct ; for 

 the ratlier deep groove and elevated ridge on the handle must 

 have fitted into a similar ridge and groove on the next plate. 

 Again, in No. 9 (PI. VIIL fig. 4 a), there is a well-developed 

 elevation upon the handle, wliich, there is no reason to doubt, 

 fell into a corresponding hollow on the plate next in succession. 

 In No. 6 (PI. Vill. fig. 1 a) there is the interesting peculiarity 

 of a raised border, developed along one margin certainly, and 

 possibly along the other, of the handle, which may be inter- 

 preted as an articulatory provision. Its function, however, is 

 not perfectly clear. 



Thanks to this series of detached plates, we obtain a little 

 additional light as to the structure of the apparatus of which 

 they were the parts. That this is not entirely sufficient to 

 remove the doubt surrounding their affinities is tolerably clear j 



