202 BULLETIN OF THE 



ml Sorkidte attain an appreciably larger size than under nearly 

 the same latitude anil degree of elevation at the eastward. The same 

 fact is also observed in the mink ; while the bears of the Pacific slope are 

 larger than from most other parts of the Continent. Whether a greater 

 abundance of their proper loot! may be the cause of this, it, is impossible 

 now to determine. They are facts, however, that, are worthy of careful 

 consideration, and they are cited here simply to call to them further 

 attention. 



It may be observed, in passing, that allied species, as the fox and wolf, vary 

 differently under the same conditions ; melanism being most developed in 

 the one at the south, and in the other at the mirth. It is also noteworthy that 

 circumpolar species follow the same law in their climatal variations that 

 obtains in the differentiation in both the fauna and flora of the northern 

 hemisphere in passing from the north southwards. As is well known, then; 

 are many species of animals and plants at the north, where their habitats 

 approximate, that are common to the two continents. Such species become 

 less and less numerous to the southwards, and beyond the tropics very 

 few occur on both the Eastern ami Western continents. In like manner, 

 specimens from towards the north of the two continents of circumpolar 

 species that range over the north temperate regions are much nearer alike 

 than those collected from near their southern limits of distribution. 



For t lie following notes on the Cetaceans of the Massachusetts coast, 

 and their local names, 1 am indebted, as previously stated, to Captain 

 N. E. Atwood, of Provincetown. For the scientific names lam under 

 obligations to Professor F. D. Cope, of Philadelphia, to whom I for- 

 warded Captain Atwood's note- for the determination of the species. 

 Professor Cope's identifications and remarks are distinguished by being 

 enclosed in brackets. 



BALiENIDJE. 



19. [Balaena cisarctica Con:.] l - Rigiit Whale. Occasional. 



" This well-known species is at times taken hen- ; in former years they 

 were; much more frequent in their visits than now. Although a straggling 

 specimen may be seen at any lime, they are generally more common 

 dining the latter part of April and the early part of May. They 

 yield a larger amount of oil than any other species that visits our 

 coast : besides which they have a large quantity of whalebone that 

 finds a ready market, known as the '"black whalebone" of commerce. 



