434 ZOOLOGY. 



or four hundred have been killed. When wounded they become furious, 

 striking from side to side with their long tusks, seizing and breaking asunder 

 the weapon with which they are attacked, and at length, placing the head 

 downwards between the fore paws, roll themselves like an immense ball 

 into the sea." 



The Avalrus was formerly met with along the Atlantic coast of New 

 England, and about the year 1650 extensive fisheries were carried on 

 along the coast of New Brunswick. Fossil species of the same genus are 

 found within the limits of the United States, one of which is described 

 under the name of Trichechus virginianus. Others, as it seems, have left 

 their remains in the old world. 



In size the walrus surpasses the largest ox, and attains twenty feet in 

 length. The body is covered with short yellowish hair. 



Group 3. Pachydermata, 



The group of Pachydermata is a very natural one amongst the Herbivora 

 'of our days. It includes those hoofed mammals which are not ruminants. 

 Among terrestrial animals they are the largest. They are characterized 

 by the thickness of their skin, to which their name has reference ; most of 

 them are bulky and heavily built, even in the species of middling size. 

 The clavicle or collar bone is absent : the pachyderms have limbs destined 

 to support the body, and not for seizing any object. They are terrestrial 

 or semi-aquatic, and constitute the natural ascending transition from the 

 Cetacea and Sirenidia. 



Fam. 1. Anoplotherid^. This family combines the characters of the 

 ruminants and those of the multungulate or many-hoofed pachyderms. 

 The skeleton still presents much of the slender and light forms of the two- 

 hoofed ruminants. The genera composing this family are all extinct, 

 having only existed during the tertiary epoch. The typical forms lived in 

 the eocene period, and towards the end of the meiocene they became less 

 numerous, disappearing comj)letely during the pleiocene period. 



The genus Anophtherium is considered as having some affinities with 

 the rhinoceros, the horse, the hippopotamus, the hog, and the camel ; and 

 indeed this is not at all surprising, for Anoplotherium has preceded all these 

 genera in the history of life upon the surface of our globe. They are the 

 prototypical or synthetical creation, combining, during the eocene, the 

 forms which were to appear distinct at a later date. Anoplotherium has 

 forty-four teeth disposed in a continuous and uninterrupted series, a charac- 

 ter found nowhere else except in man. Complete skeletons of Anoplotherium 

 are preserved in collections ; the feet are provided with only two developed 

 toes, as in ruminants ; in some species, however, there are small accessory 

 toes. The Anoplotheria were bulky and stout animals possessing a large 

 and thick tail, calling to mind that of the otters, whence the opinion that 

 these animals were divers and had habits similar to those of the hippopota- 

 mus, Eemains of two anoplotheria have been found in Paris; the^i. com- 

 638 



