EXTERNAL CHARACTERS. 31 



may be stretched to the breadth of fifteen to eighteen inches." 

 The hind feet, he says, have a length of " about two to two and a 

 half feet," the breadth, when fully extended being "two and a 

 half to three feet."* 



Dr. Gilpint gives about the same dimensions for a specimen 

 12 feet long, namely, fore-flippers, length 2 feet 5 breadth 13 

 inches ; hind flippers, length 22 inches, breadth (when stretched) 

 2 feet 6 inches. Dr. Murie gives for a specimen about 7f feet 

 long: from shoulder-joint to extreme end of first digit, 23 

 inches ; extreme length from os calcis to tip of fifth digit, 17 

 inches 5 extreme breadth, when forcibly distended, 13 inches. 

 My own measurements, taken from three unmounted skins of 

 adult males preserved in salt in the collection of Prof. Henry 

 A. Ward of Eochester, are as follows : manus, from carpal joint 

 to end of digits, 14 to 15 niches 5 transverse diameter at base, 

 9 J to 10 inches $ pes, from tarsal joint to end of longest digit, 

 15 to 18 inches ; transverse diameter at tarsus, about 7 inches. 

 The rigidity of the feet did not permit of ready expansibn. 



In respect to the tail, Dr. Murie says : " Strictly speaking, 

 the Walrus possesses no free tail, as do the Phocidce and Ota- 

 riidce; for a broad web of skin stretches across from os calcis to 

 os calcis, enveloping the caudal representative. This remarka- 

 ble elastic membrano-tegumentary expansion, reminding one of 

 the more delicate web similarly situated in Bats, has posteri- 

 orly, when the legs are outspread, a wide semilunar border 

 with little if any medio-caudal projection. What appears as a 

 tail when the limbs are approximated is in reality fibroid tissue 

 and skin 5 for the caudal vertebrae stop short about an inch from 

 the free margin." f 



The number of mammae is stated by various writers to be 

 four. According to Edwards (as quoted by Richardson ), these 

 are placed, in the adult, 15 inches apart, in the corners of a 

 quadrangle having the umbilicus in the centre. Owen and 

 Murie give them as " two abdominal and two inguinal." 



In respect to general size, authors vary greatly in their state- 

 ments, the length ranging for adults from about 10 to 12 and 

 even 15 or 16 feet, while the weight given ranges from 1,500 to 

 5,000 pounds ! Among what may be termed recent writers, Parry 



* Account of Arctic Regions, vol. i, p. 503. 



tProc. and Trans. Nova Scotia Inst. Nat. Sci., vol. ii, pt. 3, p. 123. 



t Trans. Zool. Soc. Lond., vol. vii, p. 425. 



Snppl. to Parry's Sec. Voyage, p. 340. 



