NATURAL HISTORY SOCIETY OF GLASGOW. 95 



the surface of this species is a very interesting point in the structure 

 of these old Chitons. So far as my own observation has gone, it is 

 not possessed by any of the other species. The partial flattening of 

 the middle portion of the anterior plate, and the bending down of 

 the lateral portions, give to each of them a tri-divisional appearance 

 resembling the three areas met with usually on the intermediate 

 plates in Chiton. 



The pointed, snout-like appearance, and the lateral spines, at once 

 distinguish the anterior plates of this species from that of C. 

 Dalriensis. The characters of the posterior piece are sufficiently 

 distinctive in themselves. I have much pleasure in naming this 

 species after my friend, Mr. James Geikie, LL.I) , F.R.S. 



Locality and Horizon. — Law Quarry, near Dairy, as before. 



Colled inn. — [. Smith. 



Chiton, sp. inch— (PI. L, figs. 23 and 24.) 



Obs. — One or two small plates have been found by Mr. J. Smith, 

 which appear to differ from any of the others described, when care- 

 fully and minutely examined. The anterior plates come nearest to 

 C. Geikiei, but they are proportionately higher, longer, narrower, 

 and more pointed. Lastly, the spines have not been observed. 

 The posterior margin is a little concave, and the surface for some 

 little distance inwards from the posterior margin is crowded with 

 growth lines. The intermediate plates are small and very much 

 bent. The material is too meagre to do more than casually refer to 

 these plates in passing. They may perhaps subsequently be united 

 with one or other of the other species. The surface is covered with 

 microscopic granules of the smallest size, too small almost to be 

 detected with the hand lens. 



Locality and Horizon. — Law Quarry, near Dairy, as before. 



Collection. — J. Smith. 



Genus Chitonellus, Lamarck, 1819. 

 (Hist, des Animaux sans Vertebres, vi.) 



Obs. — The genus Chitonellus, or at any rate plates of some mem- 

 bers of the Chiton idae having closer relations to it than to Chiton 

 proper, flourished extensively during the Permian period, and we 

 are now acquainted with several distinct forms from our Carboniferous 

 rocks. The deposit at Law Quarry has yielded species of this genus. 



