PROGRESS IN THE STUDY OF ANCIENT SEDIMENTS, n 



Rcmopleurides, and Agnostus. He adopts three groups 

 for the genus Calymene, viz., Calymene proper, Pharostoma 

 coj'da, and Ptychometopus n. subgen., and gives diagnoses 

 of them. T. S. Hall (14) has a " Note on the Distribution 

 of the Graptolitidae in the Rocks of Castlemaine (Australia)". 

 Some of the identifiable forms, according to the author, range 

 through the series, whilst others afford a ready means of 

 distinguishing certain facies. As Tetragraptus ranges 

 throughout the beds, they would seem to be of Arenig 

 age notwithstanding the occurrence of "what is apparently a 

 Mouograptus" . The forms recorded are similar to those of 

 the Skiddaw slates of England and the Quebec group of 

 Canada, and appear to be restricted to certain horizons of 

 the strata. With regard to the apparent Mouograptus, it 

 may be suggested that it is possibly an Azygograptus— 

 Monograptus it certainly cannot be if it be associated with 

 the graptolites occurring in the strata throughout which 

 Tetragraptus ranges. The fact that certain species appear 

 to be restricted to definite horizons of these Tetragraptus 

 beds is of interest, for until quite lately the existence of 

 definite zones in the corresponding Skiddaw and Quebec 

 beds, both of which have undergone much disturbance, was 

 doubted. 



Consideration of the contributions to our knowledge of 

 the Upper Palaeozoic or Deuterozoic (Devonian, Carbon- 

 iferous, and Permian) beds, which were made during the 

 second half of the year 1894, must be left for a future 

 article. 



BIBLIOGRAPHY. 



(1) GEIKIE, Sir A. Annual Report of the Geological Survey 



[United Kingdom], etc., for the year ending 2,1st Dec, 1893. 

 London, 1894. 



(2) DAWSON, Sir J. W. Some recent Discussions on Geology. 



Bull. Geol. Soc, Amcr., vol. v., p. 10 1. 



(3) Campbell, M. R. Bull. Geol. Soc, Amer., vol. v., p. 171. 



Rochester, N.Y. 



(4) Walcott, C. D. Bull. Geol. Soc, Amer., vol. v., p. 191. 



Rochester, N.Y. 



