118 MAMMALIA. 



annulated black and white ; there is a crest of long- bristles on its head and neck. Its tail is short, and furnished 

 with hollow truncated tubes suspended by slender pedicles, which make a rattling sound when the animal shakes 

 them. Its cranium and muzzle are singularly convex. There are other species not very different, but with the 

 head less convex, inhabiting India and Africa. [These constitute the Acanthion of M. F. Cuvier : the H. hirsuti- 

 rottris, Brandt, is however intermediate.] 



We separate from the true Porcupines 



The Atherures (Atherura, Cuv.), — 



The head and muzzle of which are not inflated, and the tail long, but not prehensile ; their feet are 



similar to those of the preceding. 



The Pencil-tailed Atherure (Hyst. fascicidata, Lin.)— The quills on the body furrowed with a groove in front, 

 and the tail terminated by a bundle of flattened horny slips, constricted at intervals. [Inhabits India and Malacca.] 



The Ursons (Erethizon, F. Cuv.), — 



Have a flat cranium, and short muzzle which is not convex : their tail is of middle length, and the 

 spines short and half-hidden in the hair. 



One species only is known, from [the Atlantic side of] North America (Hyst. dorsata, Lin.). [The E. epixan- 

 thus, Brandt, from the western side of the same continent, appears to be another. These animals produce but 

 one young at a birth.] 



The Coendous (Synetheres, F. Cuv. [Cercolabes, Brandt] ). 

 Muzzle short and thick ; the head convex above ; quills short ; and the tail, in particidar, long, 

 naked at the tip, and prehensile, as in a Sapajou or Opossum. They climb trees, and have only four 

 toes on each foot. 



In the warm parts of North America, there is a species with black and white spines, and brown-black fur 

 (Hyst. prehetisilis, Lin.) ; and a smaller kind in South America (//. insidiosa, Licht.), the prickles of which are 

 partly red or yellow, and hidden during part of the year by its long greyish-brown fur. [M. d'Orbigny is of 

 opinion that these constitute but one species. In Brandt's memoir on the Porcupines, however, they are referred 

 to different subgenera, after M. F. Cuvier ; the first, with the addition of another (S. platycentrotus), to Synetheres 

 as restricted, the other, with two more species (S. nigricans and#- affinis), to a subdivision Sphiggurus. 



The Aulacodon (Aulacodus, Tem.) 

 Incisors very broad, the upper furrowed with two grooves, and a third at their inner margin : four 

 molars as in the preceding, those of the upper jaw with a single deep fold of enamel within, and two 

 without, excepting the anterior, which has three ; in the lower jaw, the outer margin has only one 

 fold, and the inner two. There are five toes before and four behind, and some flattened spines 

 mingled with the fur. The form is that of a Rat, with the molars of a Porcupine. 

 A. swinderianus, Tem., is the only known species, from the Eastern Archipelago]. 



The Hares (Lepus, Lin.) — 



Have a very distinctive character, in their superior incisors being double ; that is to say, there is 

 another of small size behind each of them* [or, in other words, two genuine incisive teeth are present 

 in these animals, posterior to the ordinary representatives of the tusks or canines]. Their molars, five 

 in number above and below, are each of them formed of two vertical lamina; soldered together, and in 

 the upper jaw there is a sixth, simple and very small. They have five toes before, and four behind ; 

 an enormous coecum, five or six times the size of the stomach, and lined internally with a spiral layer 

 throughout its whole length. The interior of their mouth and the under part of their feet are covered 

 with hair like the rest of the body. 



The Hares, properly so called (Lepus, Cuv.), — 



Are distinguished by their long ears, short tail, hind-feet much longer than the fore, imperfect clavi- 

 cles, and antorbital space in the cranium widely pierced and reticulated. There are numerous species 

 in both hemispheres, which from their resemblance are difficult to characterize. 



[Four occur in the British islands. The Common Hare (L. timidus, Lin.), with yellowish-brown fur, which has 

 a tendency to curl; the Irish Hare (L. hibernicus), with shorter limbs and ears, and smooth reddish fur, of very 



* There is even a period when they are shedding their teeth, during whieh they appear to have three pair of upper incisors, one behind 

 the other. 



