Jdne 3, 1910] 



SCIENCE 



875 



shape and microscopic structure of the skin bones 

 of an edentate animal from the Los Angeles as- 

 phaltum beds. These bones, which are small 

 pebble-like elements in the skin, resemble closely 

 similar bones occurring in a piece of skin found 

 in a cave at Last Hope Inlet, Patagonia. They 

 are also known to occur in Mylodon, a genus of 

 ground sloths formerly living in North and South 

 America. As the structure of the skin bones in 

 Mylodon is quite diflferent from what it is in 

 Orypotherium, the form from the Last Hope 

 Inlet locality, it was a matter of interest to find 

 out to which of these genera the specimens from 

 the asphalt showed the closer resemblance. Thin 

 sections of the bones were cut and these prove 

 that Paramylodon from the asphaltum beds is 

 almost identical, in the structure of the skin 

 bones, with Grypotherium, a contemporary of 

 early man in Patagonia. 



The Restored Skeleton of Leptauclienia decora: 

 William J. Sinclair, Princeton. 

 A restoration of the skeleton of this small 

 extinct hoofed animal from South Dakota has 

 been prepared from specimens in the collection of 

 Princeton University. Hitherto only the skull 

 has been figured. The restoration shows the 

 animal to have been about twenty-one inches long 

 from tip of nose to root of tail and about ten 

 inches high at the shoulder. 



Correlation of the Pleistocene of the Neiv and 

 Old Worlds: Henry Fairfield Osborn, New 

 York. (Read by title.) 

 The Primates of the Old and the New Worlds, 

 together with Man: Giuseppe Sergi, Rome, 

 Italy. (Read by title.) 

 A Note on Antarctic Geology: William Morris 

 Davis, Cambridge. 



The lively interest now aroused in Antarctic 

 exploration suggests that the special attention of 

 geologists should be directed to a problem of great 

 interest that may possibly be solved by special 

 studies in far southern latitudes. It is well 

 known that fossil plants have been found in vari- 

 ous formations in the Arctic and Antarctic re- 

 gions, indicating the former prevalence there of 

 a much milder climate than that of to-day. Our 

 prepossession naturally favors the present polar 

 climate as having been the ordinary or normal 

 polar climate of all geological time; but inasmuch 

 as milder climates have sometimes occurred, it is 

 eminently possible that they, and not the present 

 rigorous climate, may have been the usual polar 

 climate through the geological ages. Hence a 



peculiar interest attaches to studies of the minute 

 structures of stratified formations, particularly 

 of such as are of continental origin; for from 

 such studies it may well be possible to determine 

 climatic conditions even in the absence of fossils. 

 It is fitting that attention should be directed 

 to this problem by its discussion before a society 

 that, more than any other in this country, has 

 promoted renewed interest in Antarctic explora- 

 tion. 



The Italian Riviera— A Study in Geographical 

 Description: William Morris Davis, Cam- 

 bridge. 



After a geographer has seen a district it is his 

 responsibility to describe it in such a manner 

 that other geographers who have not seen it may 

 get as clear a conception of it as possible. For 

 this purpose experiment is here made on the pic- 

 turesque Riviera Levante, between Genoa and 

 Spezia, following the method which may be called 

 the method of " structure, process and stage " ; 

 because the land forms observed are treated first 

 in terms of the rock structures of which they are 

 composed; second, in terms of the processes of 

 sculpture that have worked on their surface; 

 third, in terms of the stage of development reached 

 by these processes in their task of the complete 

 destruction of the lands. Briefly stated, the 

 Riviera Levante is a district of deformed strata, 

 for the most part sandstones and limestones of 

 similar resistance, which in an earlier cycle of 

 normal erosion was reduced to small relief; the 

 lowland thus produced was then tilted to the 

 southwest, and in this attitude it was maturely 

 dissected by normal erosive agencies and maturely 

 retrograded by the sea, with the result of having 

 all its spurs cut off in great terminal facets along 

 a simple shore line. This stage of development 

 having been reached, the district was in recent 

 time very gently tilted on an axis through its 

 middle at right angles to the general coast line; 

 and thus slightly elevated to the northwest and 

 depressed to the southeast; as a consequence, an 

 abraded marine platform was revealed in increas- 

 ing height and breadth to the northwest; while 

 the valleys and sea-cliff facets were submerged td 

 increasing depth towards the southeast. Since 

 this change took place, the streams have cut down 

 mature valleys across the raised platform, and 

 the sea has cut away its outer margin; while on 

 the other side of the axis of tilting, the drowned 

 valleys have been filled with delta deposits, and 

 the cliff-facets have been somewhat steepened at 



