June 18, 1897.] 



SCIENCE. 



955 



students in the graduate departments, 909 in the 

 College of Science, Literature and the Arts, and 

 ISl in the College of Engineering, Metallurgy 

 and the Mechanic Arts. 307 degrees were con- 

 ferred at the commencement exercises on 

 June 3d. 



Of the £30,000 immediately required towards 

 the endowment fund of the new SheflBeld Uni- 

 versity College £24,000 has already been sub- 

 scribed. 



De. a. Hill, Master of Downing College and 

 lecturer on human anatomy, has been elected 

 Vice-Chancellor of Cambridge University for 

 the coming year. 



At Columbia University Mr Herbert M. 

 Richards has been appointed tutor in botany ; 

 Dr. James Ewiug, instructor in clinical micro- 

 scopy ; Dr. Charles Norris, tutor in pathology ; 

 Mr. Benjamin Jakish, assistant in chemistry ; 

 Mr. William E. Day, assistant in physics, and 

 Mr. James H. McGregor, assistant in zoology. 



At the Teachers' College, New York, Mr. 

 Richard E. Dodge has been promoted to a 

 professorship of geography, and Mr. C. E. 

 Bickle to an associate professorship of mathe- 

 matics. 



De. Chaeles St. John, of the University of 

 Michigan, has been made professor of physics 

 at Oberlin College. 



Peofessor William A. Rogees has resigned 

 from the chair of physics and astronomy at 

 Colby University, and it is reported that he 

 has accepted a professorship of physics at Alfred 

 University. 



DISCUSSION AND CORRESPONDENCE. 

 THE DISTEIBUTION OF MAEINE MAMMALS. 



To THE Editor of Science : The interesting 

 memoir of Dr. P. L. Sclater ' on the Distribution 

 of Marine Mammals' (Science, V., 741-748) ig- 

 nores previous investigators, and the general 

 reader might, therefore, receive the idea that 

 the subject under consideration has been en- 

 tirely neglected by other writers, and would 

 be also liable to suppose that his ' six sea- 

 regions ' were of equal value. In both postu- 

 lates he would be entirely mistaken. The bear- 

 ings of marine mammals on zoogeography and 

 the differentiation of the ' regions ' into primary 



and secondary ones have been frequently con- 

 sidered by others. 



Dr. Sclater considers that, ' ' for the geography 

 of marine mammals, the ocean may be most 

 conveniently divided into six sea- regions, which 

 are as follows :" 



' I. Regio Arctatlantica.' 



'II. " Mesatlantica.' 



' III. " Indopelagica.'' 



'IV. " Arctirenica.' 



'V. " Mesirenica. ' 



' VI. ' ' Notopelagica. ' 



The characteristic types of each of these re- 

 gions are named, but Dr. Sclater has evidently 

 overlooked some sources of information and 

 hence has unduly restricted certain forms. Thus, 

 the Balsena mysticetus is by no means ' peculiar 

 to Arctatlantis,' but has been the object of an 

 extensive fishery north of Bering strait.* 

 Nor are Delphinapteriis and Monodon ' not found 

 elsewhere,' for they also occur in Arctirenia. 

 Further, JBerardius is not restricted to the 

 Notopelagian area, for a species occurs in the 

 North Pacific.f It follows that these extensions 

 of the ranges of the several genera diminishes 

 the value of the regions supposed to be distin- 

 guished by their exclusive possession. If we 

 have regard for the most characteristic aggre- 

 gates of sea mammals, we are led to three 

 primary divisions, viz : 



Arctalian f I. Regio Arctalantica. 

 realm. \ IV. " Arctirenica. 



m ■ T f II. " Mesatlantica. 



Tropicalian ^J■r u t j i ■ 



realm 1 ^^^- Indopelagica. 



(V. " Mesirenica. 



Notalian ( ^tt h -nt j. i • 

 realm. 1^1- Notopelagica. 



The Arctalian realm is characteristic from 

 the development of the Phocine Phocids, the 

 Odobaenids or ' Trichechidae ' and the Delphinap- 

 terine Delphinids. The North Atlantic and 

 North Pacific ' sea-regions ' are distinguished 

 from each other by features of much inferior 

 importance. 



The Tropicalian realm is remarkable for 

 the development of the existing Sirenians 

 and likewise of numerous Delphinine Del- 



*See Dall in Science (n. s. ), V., 843, May 28, 1897. 

 tBerardius Bairdii Stejneger,Proc. U. S. Nat. Mus., 

 VI., 75, 1883. 



