34:2 J. B. Hatcher — Geology of Southern Patagonia. 



both, forms are found, no matter how dissimilar they may be, 

 yet showing approximately the same degree of development 

 along those lines of progression common to both, it is only fair 

 to consider beds containing such forms as of approximately 

 the same geological age, and such correlation of the deposits 

 of Patagonia will, it is believed, receive the sanction of most 

 paleontologists and geologists, until good reasons are produced 

 to show that it is at fault. It was largely for the purpose of 

 securing material with which to make such comparisons that 

 our expedition to Patagonia was undertaken. Several tons of 

 most excellent fossils were procured from various horizons in 

 the Santa Cruz beds, among which are the skulls and greater 

 portions of the skeletons of nearly every genus reported from 

 these beds. This material is being rapidly freed from the 

 matrix and prepared for study, and in a short time it will be 

 possible to compare these forms, point for point, with the 

 skeletons of animals found in our own Tertiary deposits, the 

 age of which has been determined beyond reasonable doubt, 

 both from paleontological and stratigraphical evidences. While 

 the final results of such comparisons are yet to be attained, 

 enough has already been done to demonstrate the compara- 

 tively modern aspect of the fauna of the Upper Santa Cruz 

 beds. For the benefit of those interested and who may not 

 have had an opportunity of studying for themselves the figures 

 and descriptions already published by Dr. Ameghino, I present 

 here in figs. 4, 4a, 5, the metatarsals and superior dentition of 

 one of the Proterotheridee, drawn from part of No. 15107 in 

 our collection. ]STote the complex structure of the molars and 

 pre-molars, the molariform condition of the latter, the long 

 diastema, the absence of incisors, etc., in the dentition, while 

 in the metatarsals there is the very great tendency to mono- 

 dactyl ism, as shown by the rudimentary character of metatar- 

 sals II and LY, and the extremely well-developed metapodial 

 keel on metatarsal III. These or other characters, equally 

 indicative of a high degree of specialization, are met with in 

 nearly every group of animals in these beds. In consideration 

 of the stratigraphic position of the Santa Cruz beds and the 

 degree of specialization exhibited by the mammalian remains 

 found in them, it is difficult to see how they can pertain to a 

 period more remote than Miocene. 



Pliocene. 



The Gape Fairweather heels. — In this Journal for September 

 last, the author described and gave a section of certain marine 

 deposits found near Cape Fairweather, overlying the Santa 

 Cruz beds, and named them the Cape Fairweather beds. At 



