230 Scientific Intelligence. 



2. On the Classification of Lake Basins, by Wm. M. Davis. 

 — This paper makes nearly 70 pages of vol. xxi of the Proceed- 

 ings of the Boston Society of Natural History. It reviews the 

 kinds of lake-basins and considers their modes of origin. Among 

 the conclusions presented are the following : that the Great 

 Lakes of North America are not a result of glacial excavation; 

 that while there are rock-basins of moderate size which are pre- 

 sumably of glacial origin, these are far out numbered by drift- 

 barrier basins and drift basins; that the presence of drift ami 

 aliu\ ial harriers below the Swiss lakes, so far as effective, obviate 

 the necessity of considering them orographic or glacier-erosion 

 basins; that the kettle-holes and other depressions over the drift 

 deposits, unst ratified and st ratified, may in part have originated 

 in hollows occupied by isolated ice-masses during drift deposition, 

 as suggested for American examples by Upham (an explanation 

 applied by Peschel, as Mr. Davis states, to account for the 

 preservation of Lake Xeufchatel and its neighbors), or they may 



3. TJie (Jatskill region. — A paper on the Little Mountain, east 

 of the Catskills, by Wm. M. Davis, giving instructive sections of 

 the rocks of these elevations and of the region between the Cat- 

 ski IN and I he 1 hid soi i. is contained in vol. iii o| Appalachia, No. 1. 



se species 6 are Mammals, 132 Reptiles, ■_'!'. 

 mites, 477 Ammonites, <; Teuthids, •_' 1 Nautili 

 5 Gasteropods, 924 Dimyurk's, 444 Monomya 

 )ds, 51 lirvozoans. 64 Crustaceans, 45 Annelids 

 175 Cmlenterates, loo Rhizopods, 11 Aniorpho 



