Mr. G. Busk on the Dentition of Fossil Bears. 399 



prints. He was of opinion that the tracks were produced by fish 

 endowed with stiff defences to their pectoral or ventral fins. Whether 

 the Pteraspis possessed such defences he was not aware, though he 

 thought it not at all improbable. 



4. " On a new Lingulella from the red Lower Cambrian rocks of 

 St. Davids." By J. W. Salter, Esq., A.L.S., F.G.S., and H. 

 Hicks, M.D. 



Until very recently not a vestige of any organic remains had oc- 

 curred in the red rocks of the Lower Cambrian series. The fossil 

 now in question, which has been obtained from these deposits, is 

 unquestionably a Lingulella ; and although apparently of the same 

 species as one which Mr. Salter names Lingulella ferruginea, very 

 common in the lowermost of the layers which have yielded Para- 

 doxides, this older form is distinguished by the varietal name of 

 L. ferruginea var. ovalis, Hicks. 



5. "Observations on certain Points in the Dentition of Fossil 

 Bears, which appear to afford good diagnostic characters, and on 

 the relation of U. priscus, Goldf., to U. ferox." By George Busk, 

 Esq., F.R.S., F.G.S. 



After noticing the difficulties which attend the study of the bones 

 of the skeleton generally in Fossil Bears, and the somewhat confused 

 and contradictory opinions as to the distinction of species which 

 have arisen in consequence, Mr. Busk stated that his object in the 

 present communication was merely to call attention to some points 

 in the dentition which seemed to afford more certain and more 

 readily ascertainable characters than could at present be drawn from 

 the bones, and which, at any rate in the absence of other evidence, 

 were a sufficiently sure guide in the distinction of species. 



The characters derived from the teeth depend 



1. On their dimensions, absolute and relative. 



2. On their form. 



It is not necessary, however, to consider all the teeth. The 

 canines vary too much even within the limits of one species to be of 

 much utility ; and, with certain exceptions, the differences exhibited 

 in the molars are not sufficiently marked to allow of their being 

 employed. 



The teeth upon which reliance is to be placed are the upper and 

 lower fourth premolars, and the last molar in each jaw ; and the 

 distinctive characters of these teeth in U. spelceus, U. priscus, U. 

 ferox, and U. arctos were pointed out. 



It was also endeavoured to be shown that, in the size, proportions, 

 and form of the teeth, no essential differences could be perceived 

 between U. priscus and U. ferox ; and the opinion was expressed 

 that, so far as cranial and dental characters are concerned, those two 

 species are at present indistinguishable. 



6. " On the Geology of the Province of Canterbury, New Zea- 

 land." By Julius Haast, M.D., F.R.S., F.G.S. 



The Southern Alps in the Province of Canterbury were stated to 



