4:06 Scientific Intelligence. 



and the rows of small teeth and the great nuchal spine are seen in 

 place or nearly so ; and we see that the teeth lie flat on the jaw in 

 successive rows as in modern sharks. We see also that there were 

 bands of very small teeth on the gill-arches quite different in 

 form from those of the jaws, and that the latter are of different 

 forms in different parts of the mouth, so that if found separated 

 they might be referred to distinct species. 



These specimens enable true species to be established, as dis- 

 tinguished from those founded merely on detached teeth and 

 spines, and of these four are described and figured, besides a 

 doubtful one, and spines of the allied genera, Tubulacanthus and 

 Br achy acanthus, etc. 



These Carboniferous sharks, of moderate size and armed with 

 -sharp teeth, must have devoured the smaller ganoids of the estu- 

 aries and lagoons, and probably also the larvae of Batrachians, 

 and the smaller aquatic species of these animals. Coprolites 

 which are found in the same beds are usually filled with the scales 

 of small ganoids. Both in America and in Europe the abundance 

 -of spines and teeth in some of the coal shales testifies to the num- 

 bers of these predaceous fishes, and the presence of their teeth in 

 the roofs of coal beds, and even in some cases in the coal itself, 

 shows that they ventured into fresh water and even into the shal- 

 lower ponds of the coal swamps. 



Fritsch deserves the utmost credit for his painstaking and care- 

 ful wor,k on these fossils, and his work should be in the hands of 

 all students of Carboniferous batrachians and fishes. j. w. d. 



12. On fossil plants collected by Mr. R. A. McConnell on 

 Mackenzie River and by Mr. T. C. Weston on Bow River ; by 

 Sir J. William Dawson. Trans. Roy. Soc. Canada, vol. vii, sect, 

 iv, 1889. — Twelve species are here enumerated, two of which are 

 new, the remainder having been found in some of the Arctic 

 localities. Of the remainder, seven have previously been found 

 in the Mackenzie River region, all but one of which are also 

 common to the Fort Union series along the 49th parallel, pointing 

 strongly to the close relationship between the Mackenzie River 

 beds and those of the Fort Union group. 



The fine oak leaf collected by Mr. Weston at Calgary (Fort 

 Union) is probably correctly referred to Quercus platania / but 

 the specimen figured by Professor Lesquereux in his " Tertiary 

 Flora," which comes from Carbon, Wyoming, is probably not 

 that species, being a palmi nerved leaf. In this paper Sir William 

 Dawson manifests a willingness to regard the Fort Union group 

 as belonging to the Tertiary system, while admitting that it 

 forms a part of the Laramie series in general, the lower portion 

 of which is conceded to be Cretaceous. l. f. w. 



13. The Bala Volcanic Rocks of Caernarvonshire and asso- 

 ciated rocks, being the Sedgwick prize essay for 1888, by Alfred 

 Haeker, M.A., F.G.S., Demonstrator in Geology (Petrology) in 

 the University of Cambridge. 130 pp., 8vo. — This memoir con- 

 tains the results of a careful stratigraphical and petrological study 



