122 



NATURAL HISTORY. 



found elsewhere at Mozambique. They show a resemblance to the Hystricine Rodents in the 

 structure of the lower jaw, the angular portion of which springs from the side of the bony case of 

 the lower incisor ; and the palate between the molars is narrower than in the Spalacinte. The best 

 known of the six species inhabiting the Cape of Good Hope is the STRAND MOLE-EAT (Bathyergus 

 maritimus), which is nearly as large as a small Rabbit, its length being about ten inches, witli a 

 tail two inches in length. In general form it resembles the species last described ; it has small but 

 uncovered eyes, a broad nose, no external ears; very long, compressed, and powerful claws on all the 

 toes, except the thumb of the fore-feet, which has a crooked nail ; four molars on each side, and long 

 white incisors, of which the upper ones are strongly grooved in front. The colour of the fur is 

 greyish-white, with a yellowish tint on the upper surface. The tail has a sort of radiating tuft of 

 hairs at the end. The Strand Mole-rat lives entirely in sandy localities near the sea-shore, and 

 especially in the sand-hills or dunes which fringe the coast of the Cape of Good Hope in some parts. 

 Here it burrows freely in all directions, its galleries generally radiating from several central points, 

 and joining in various places. It avoids the light as much as possible, and if by chance it is exposed 

 on the surface it is exceedingly helpless. Very little is known of the habits of this species, which 

 probably feeds chiefly on roots like the other members of the family. It is regarded as mischievous, 

 as it undermines the ground so much as to make it unsafe to ride over. The colonists, therefore, often 

 destroy it by various means. The enamel folds of the teeth become effaced with use. 



The Georychi, five species of which inhabit Cape Colony, resemble the preceding species, but 

 are smaller and weaker. The claws of the fore-feet are shorter and weaker, and the upper incisors, 

 which are long and arched forward, are not grooved. The best-known species is the so-called CAPE 

 MOLE-EAT (Georychus capensis). In the Mozambique species (Hell&phobius argenteo-cinereus) there 

 are six molars on each side above and below, and the second toe of the hind feet is the longest. In 

 most other characters it resembles Georychus. 



FAMILY IX. GEOMYIDJE, OR POUCHED RATS. 



The Pouched Rats, or Pocket Gophers, and the Pouched Mice of North America, constitute a 

 family distinguished from all the preceding forms by the presence of a pair of great cheek-pouches, 

 opening outside and not inside the mouth (see figure). These 

 cheek-pouches are haiiy inside throughout. The angular 



portion of the lower jaw is 

 strongly twisted, the molars are 

 four in number on each side in 

 each jaw, and the squamosal bone 

 is very large. In external cha- 

 racters the animals of this family 

 present considerable diversity, 

 which has led to their being 

 divided into two well-marked 

 sub-families, the distinctive pecu- 

 liarities of which are of such 

 importance that Dr. Coues has 

 raised them to the rank of dis- 

 tinct families. The GEOMYIN^E, 

 or Pouched Rats, are more or less 

 Rat-like animals, in which the feet are five-toed, and all the toes furnished with claws, those of the 

 fore feet being very strongly developed ; and the tail is short. Certain other characters are presented 

 by the skull. The outline of this part, including the zygomatic arches, is almost quadrangular; the 

 infra-orbital opening is far in front of the jugal process ; the malar bone extends forward to the 

 lachrymal. 



Of the animals thus characterised, the Continent of North America possesses, according to Dr. 

 Coues, seven species, and they are met with from Hudson's Bay and the Columbia River in the 

 north, as far south as Mexico. The best-known species, the COMMON POCKET GOPHEE (Geomys 





MOLAR TEETH OF THE MEXICAN 

 POUCHED RAT. 



UNDER SURFACE OF THE HEAD OF 

 HETEROMYS. 



