During Triassic and Jurassic Periods 205 



mention of such has been made in the strata of the "Kota" 

 beds of India, while others might further have been in- 

 cluded. Further Mansell-Pleydell in speaking on "The 

 Geology of Dorset" (75^:408) says: "The Kimmerldge 

 Clay of the vale of Blackmore is less bituminous than that 

 of the Kimmeridge district; where it is upwards of sixty 

 feet thick, and strongly impregnated with bitumen, giving 

 off a disagreeable smell. It burns vividly with a bright and 

 clear flame, but is unfit for ordinary use as fuel. . . It 

 has an unpleasant odor when burning, resembling petro- 

 leum, and yields a reddish ash. The volatile matter of the 

 richer beds is upwards of 73%; the solid mineral matter 

 being only 27%." 



Finally a noteworthy study on the Australian Jurassic 

 is A. S. Woodward's "Fossil Fishes of the Talbragar Beds 

 of Australia," that may be of Kimmerldgean age. In a pre- 

 liminary notice by T. W. E. David and E. F. Pitmann it is 

 said: "the fish-beds proper form the lowest of the three 

 members into which, on lithological grounds, the deposit 

 to which they belong may be divided. They consist of lami- 

 nated hard siliceous shales, cherty in places, rendered ochre- 

 ous by ferruginous infiltrations and traversed by joints" 

 "Fish and plants are so abundant that it is difficult to find 

 even a small fragment of the shales devoid of them. The 

 plants are preserved in the form of siliceous impressions, 

 their pure white color contrasting strongly with the ochre- 

 ous tint of the enclosing shale." The plants included are 

 Thinnfeldia odontopteroides, Podozamites lanceolatus, 

 Neiiropteridiufti australe, and Taeniopteris daintreei. 

 Associated with them and with the fishes was a cicadeous 

 insect. The perfect condition of the plants, the insects, 

 and the fishes, suggests one of two possible modes of origin 

 for the rocks and the state of the organisms. Either they 

 became suddenly entombed and cased up by siliceous vol- 

 canic dust, or some siliceous thermal lake area, by sudden 

 bursting and discharge of its contents, killed and enclosed 

 the organisms intact. Future detailed study may yet settle 

 the question. 



The fishes as determined by Woodward are of excep- 

 tional interest in the present inquiry. They Include a species 



