498 Scientific Proceedings, Royal Dublin Society. 



too much, I should be glad to have the benefit of your views on this sub- 

 ject. The Fauna of the 'Alpine Trias' — which occurs high up on the 

 west coast — is well illustrated in Exploration of 40th Parallel, vol. iv., 

 plates 10 & 11, and in Palaeontology of California, vol. i., plates 3-6. 



' ' Tours truly, 



"GEORGE M. DAWSON. 



"Rev. Prof. S. Haughton, F.R.S. 



"Prague, 

 li 31st December, 1886. 



" Mt dear Ball — You must excuse me that I did not answer your 

 kind letter earlier, but it had somehow miscarried, so that I received it 

 about a fortnight later than the book. 



" The fossils about which you wish to have my opinion have aroused 

 curiosity already on several sides, and about a year ago Professor 

 Neumayer, of Vienna, sent me a number of plaster casts of the species, 

 taken from the originals at Dublin, to ask my opinion about them. 



"As far as I can judge the matter, it seems to me that there cannot 

 be much doubt that Ammonites M l Clintochi is a Jurassic species, but 

 rather of middle Jurassic than of Liassic affinities. This opinion has also 

 been expressed by Neumayer in the Denksch. d. Kais. Acad, der 

 "Wissensch., Yienna, vol. i., Die Geographische Yerbreitung der Jura 

 Formation, p. (141), 1885, where the species is redescribed and figured. 



" The Avicula that has also been found at the same localities might be 

 Triassic, but j ust as well it might be Jurassic, and there can be drawn no 

 conclusion from that species. So, on the whole, the probability remains 

 that in these high latitudes Jurassic beds are exposed. 



" The Triassic species described by "White from Idaho, in his Contri- 

 butions to Palaeontology, and later on in the 40th Parallel Report, are 

 quite different things, and only the Avicula show at all any similarity. 

 Such a similarity is, however, of no value whatever. 



"Yery sincerely yours, 



"W. WAAGEN. 



"V. Ball, M.A., F.R.S." 



