33 



A few years since, in excavating for a ship canal through 

 Spuyten Duyvil Creek, a portion of a tusk of a Mastodon 

 (Mastodon americanus) was unearthed. This fragment is now 

 in the collection of the American Museum of Natural History, 

 New York City. 



The Porcupine, Varying Hare, Fisher and Sable were prob- 

 ably not uncommon in this region in early times, but have 

 since been exterminated. There are other species now found 

 in comities adjoining Westchester, some of which will prob- 

 ably be recorded from here, but these have been excluded 

 from the list. Among them are the Short-tailed Weasel, 

 Brewer's Mole, Red-backed Mouse, and Cave Rat (Mearns 7 ). 



Didelphis virginiana Kerr. Opossum. 



The Opossum is an animal whose range has been greatly 

 extended of late years. I recently received from Mr. C. A. 

 Deyo a specimen which was taken in Schoharie, N. Y., and 

 have since heard from him .that several others have been 

 taken there. 



On Sept. 1, 1899, I found a freshly killed Opossum on the 

 beach at Hastings. This specimen is now in the collection 

 of the American Museum. 



Under date of February 20, 1901, Mr. J. H. Quinby of 

 Armonk, Westchester County, writes me, 'about seven of 

 them have been caught near here inside of two years.' 



Although heretofore unrecorded from the east bank of the 

 lower Hudson River, it is quite common on the west bank. 



Dr. E. A. Mearns 7 (p. 330), speaking of this animal says, 

 'In the Highlands, the Opossum has always been fairly 

 common since my boyhood and hence long before its too 

 " successful " introduction on Long Island, N. Y.' 



Tursiops tursio (Fabricius). Porpoise. 



It is probable that this species of porpoise occurs within 

 the county limits in the waters of Long Island Sound, as it 



