﻿Supposed Silurian Fish-tooth. 461 



British Association for the Advancement of Science. In 

 the discussion which followed, Professors L. C. Miall, the 

 President of the Section, and W. E. Hoyle, its Eecording 

 Secretary, expressed their opinion that the interpretation 

 of the specimens suggested in the paper was probably the 

 correct one.) 



Note on a Fish Tooth from the Upper Arisaig 

 SERIES OF Nova Scotia.^ 



Dendrodus Arisaigensis. 



Side view of the only specimen known to the writer. 



Twice the natural size. 



The only indication of the existence of vertebrate 

 animals in the Silurian rocks of Canada that has yet been 

 recorded is a single specimen of a Pteraspidian fish 

 discovered by Dr. G. F. Matthew in the Nerepis hills 

 of southern New Brunswick in 1886. This specimen, 

 which consists of the rostrum, the lateral cornua, the 

 dorsal and ventral scutes, and some other plates of the 

 anterior armature of the fish-, was subsequently described 

 by its discoverer as the type of a new genus, under 

 the name Diplaspis Acadica, though Mr. A. Smith 

 Woodward claims that it should be referred to Lankester's 

 genus Cyathaspis. 



1 Read Aug. 21, 1897, in Section C (Geology) at the Toronto meeting of the British 

 Association. 



