Miscellaneous. 303 



Genus Cyrtodonta, Billings, 



In this genus, including its sub-genus Vanuxemia, the number 

 of teeth is variable. There are from two to eight anterior, and 

 from two to four posterior teeth. When I described the genus I 

 figured several species with three anterior teeth, and stated that 

 C. rugosa appeared to have four, while V. Bayfieldii was repre- 

 sented with seven. It would appear also that Professor Hall has 

 observed a species with five, as he has stated in a recent publica- 

 tion that the genus has three, four or five anterior teeth. During 

 the present year, Mr. Bell, of the Geological Survey, has collected 

 many specimens, apparently of several species, which exhibited 

 two, three, four, six and in one apparently eight anterior teeth. 

 It is quite clear, therefore, that the number is variable, as stated 

 by me in my description of the sub-genus. In consequence of 

 these discoveries, the only distinctive character of the sub-genus 

 Vanuxemia is the terminal position of the beaks, and it may be 

 necessary to suppress it altogether. 



MISCELLANEOUS. 



Lower Carboniferous Coal-Measures of British America. A 

 paper by Principal Dawson giving an account of the 

 present state of knowledge respecting these interesting 

 beds and their fossils, was read before the Geological So- 

 ciety of London, at its meeting of April 28th. The fol- 

 lowing is from Abstracts of Proceedings of the Society. 



H Deposits indicating the existence of the Coal-flora and its as- 

 sociated freshwater fauna at the beginning of the Carboniferous 

 period, are well developed in Nova Scotia and New Brunswick, 

 with a clearness and fullness of detail capable of throwing much 

 light on the dawn of the terrestrial conditions of the Coal-period, 

 and on the relations of these lower beds to the true coal measures. 

 This lower series comprises shales and sandstones (destitute of 

 marine remains, but containing fossil plants, fishes, entomostraca 

 worm-tracks, ripple and rain marks, sun cracks, reptilian foot- 

 prints, and erect trees) and great overlying marine limestones 

 and gypsums. These are distinct from the true coal-measures 

 by their position, mineral character, and fossil remains. In the 

 western part of Nova Scotia (Horton, Windsor, &c) the true (or 

 Upper and Middle) Coal-measures are not developed ; and here 

 the Lower Carboniferous marine deposits attain their greatest 



