266 



SCIENCE. 



[N. S. Vol. XI. No. 268. 



I did, however, seriously questioa both their 

 Cretaceous age and the stratigraphic position 

 assigned to them by the Amegliinos. From a 

 study of Dr. Ameghino's description of the 

 mammalian fauna found in them, I advanced 

 the opinion that there were mingled together 

 in the so-called Pyrotherium fauna, representa- 

 tives from two or more distinct horizons. This 

 opinion Dr. Ameghino has since admitted to be 

 a fact and has separated his Pyrotherium beds 

 into two distinct formations which he separates 

 by a long time interval. My succeeding two 

 years of field-work in Patagonia have further 

 convinced me as to the correctness of my former 

 views regarding the Pyrotherium beds. 



In referring on page 30 to the paleontologic 

 evidences advanced by myself regarding the 

 age of the Pyrotherium beds, Dr. von Ihering 

 is quite i-ight in saying that the tooth mentioned 

 and figured by myself as belonging doubtfully 

 to Pyrotherium, is a tooth of Astrapotherium, 

 and also in maintaining that in the process of 

 development of any mammalian phylum, cer- 

 tain organs may early attain a considerable de- 

 gree of specialization, while the animal as a 

 ■whole remains quite primitive in its structure. 

 Everyone I presume will readily grant this, but 

 ■would Dr. von Ihering have us entirely overlook 

 the extremely close relationships, brought out 

 on almost every page of Dr. Ameghino's papers 

 on the Pyrotherium fauna, as existing between 

 the so-called Cretaceous fauna of the Pyrothe- 

 rium beds and that of the Santa Cruz beds, 

 which latter are now known to be not older than 

 Miocene? Many of the mammals described by 

 Ameghino from the Pyrotherium beds are 

 scarcely specifically distinguishable from allied 

 forms in the Santa Cruz beds. In a few in- 

 stances Ameghino has himself admitted that he 

 can not distinguish forms from the Pyrotherium 

 beds from well-known Pliocene and Pleistocene 

 animals. Among such may be noticed the large 

 gravigrade edentate which he is unable to dis- 

 tinguish from Mylodon, more than likely for the 

 very good reason that it is a tooth of Mylodon 

 from thePleistocene deposits that occur through- 

 out the greater part of Patagonia. 



Considering the highly specialized character 

 of the Pyrotherium fauna and its remarkably 

 close relationship as a whole to the Santa Cruz 



fauna, in connection ■sv'ith what we already 

 know of the character of the stratigraphic work 

 of the Ameghinos in Patagonia, the Cretaceous 

 age of the Pyrotherium beds can no longer 

 be seriously considered. Moreover the strati- 

 graphic observations of Dr. Roth, Seiior Mer- 

 cerat and myself are all at variance with such a 

 position for them. 



On page 45 Dr. Von Ihering includes the 

 Cape Fairweather beds in the Tehuelche for- 

 mation as is also done by Ameghino. If I mis- 

 take not the term Tehuelche foi'mation -was 

 proposed by Doering for the great bowlder or 

 shingle formation of Patagonia. Unfortunately 

 I have never been able to see Doering' s paper. 

 If I am correct in this the Cape Fairweather 

 beds should not be included in the Tehuelche 

 formation since they are quite distinct and un- 

 conformable as I have been able to observe at 

 several different localities. The Cape Fair- 

 weather beds are Pliocene while the Bowlder 

 formation is unquestionably Pleistocene. A 

 curious account of the relations of these two 

 deposits has been published by Dr. Ameghino 

 in the Geological Magazine, for January, 1897. 

 On page 17 in speaking of these two series of 

 beds he says, after quoting at some length from 

 a letter from his brother, Charles Ameghino : 

 " According to this the bowlders were deposited 

 at the bottom of the sea and over them there 

 extended at other periods a vast formation of 

 marine shells." In this instance Dr. Ameghino 

 has again reversed the true stratigraphic rela- 

 tions as he did for many years with the Pata- 

 gonian, Supra Patagonian and Santa Cruz beds. 

 J. B. Hatcher. 



Geological Survey of Canada. By George Mer- 

 cer Dawson, C.M.G., F.R.S., etc. , Director. 

 Annual Report. (New Series.) Vol. X. Ot- 

 tawa, December, 1899. 



This volume, comprising 1046 pages of text 

 accompanied by eight maps and illustrated by 

 twelve plates and a number of figures in the 

 text, has just been issued by the Department 

 and forms publication No. 679 of the Catalogue 

 of volumes published by the Canadian Survey. 

 It is addressed to the Hon. Clifford Sifton, 

 M.P., Minister of the Interior, and contains 

 many valuable reports of exploratory and geo- 



