957 



MURID.E. 



958 



Sir John Richardson, from whose ' Fauna Boreali- Americana ' the 

 above description is abridged, states that in some specimens the 

 yellowish-brown colour occupies as much space as the darker colour 

 of the back ; in others the latter encroaches so much on the sides as 

 to leave merely a narrow yellowish line next the white; whilst in 

 autumn specimens, where the animal has just acquired a new coat of 

 fur, the dark colour of the back adjoins the white of the belly. 



This appears to be the Labrador Rat of Pennant ; Gerbillus Hud- 

 sonius of Rafinesque-Smaltz ; Mus Labradorius of Sabine ; Gerbillns 

 Labradorius of Harlan ; Labrador Jumping House of Qodman ; and 

 Katse (the leaper) of the Chepewyan Indians. 



Sir John Richardson remarks that Pennant, in his ' Arctic Zoology,' 

 first described a specimen of this animal, sent from Hudson's Bay by 

 Mr. Graham, to the museum of the Royal Society. Afterwards, in 

 the third edition of his ' History of Quadrupeds," he is inclined to 

 consider it as identical with the Mia longipes of Pallas (the Dipus 

 meridianus of Gmelin), an inhabitant of the warm sandy deserts 

 bordering on the Caspian Sea. This opinion, which, in the opinion of 

 Sir John, can scarcely be correct, was, he says, formed from an 

 imperfect inspection of the Hudson's Bay specimen whilst it was 

 suspended in spirits, and is opposed by differences in colour and other 

 characters which he himself points out. From Pennant's time until 

 Mr. Sabine described an individual brought from Cumberland House, 

 on Captain Franklin's first journey, the Labrador Jumping Mouse 

 does not, continues Sir John Richardson, appear to have attracted the 

 notice of naturalists. Pennant, he observes, mentions a yellow lateral 

 line in his specimen, which did not exist in the one Mr. Sabine 

 described, but this difference Sir John Richardson attributes solely to 

 the season in which they were procured. Mr. Sabine's specimen, he 

 remarks, was mutilated in- the tail, an accident very common to the 

 whole family of Rats; and Pennant, under the name of Canada 

 Jerboid Rat, and Colonel Davies, under that of Dipus. Canodensit, 

 describe another Jumping Mouse, which seems to differ from this in 

 having ears shorter than the fur, but in other respects to be very 

 similar to it. 



After further observing that the Gerbittua Canadensisof Dr. Godman 

 agrees in description with Rafinesque-Smaltz's O. soricinus (Desm.), 

 but has larger ears than the Canada Rat of Pennant, and that a 

 specimen in the Philadelphia Museum, described by Dr. Harlan under 

 the name of G. Canadentit, appears to be entirely similar to the 

 Labrador species, Sir John Richardson concludes by remarking that 

 it is evident that the Jumping Mice inhabiting different districts of 

 America require to be compared with each other before the true 

 number of species and their geographical distribution can be ascer- 

 tained. 



It is common in the Fur Countries as far north as Great Slave 

 Lake, and perhaps farther ; but Sir John Richardson was not able to 

 gain any precise information respecting its habits. 



Pedete* (Illiger; Hdamyt, F. Cuvier). Head large, flattish; muzzle 

 thick ; ears long. Anterior extremities with five toes armed with 

 very long claws; posterior extremities very long, 4-toed. Tail long 

 and very bushy. Four pectoral mammae. Molars simple, with two 



lamina:. 



2 4 i 



Dental Formula : Incisors, ; Molars, 



2 4 4 



:20. 



Teeth of (Uclamyi) Pcdctei. 



1'. C'aptntit, the Grand Gerbo of Allamand ; Spring-Has, or Jumping 

 Hare of the Dutch ; and Aerdmannctje of the Hottentots. It is the 

 Ili/nu Cafftr of Zimmerman, Schreber, and Gmelin. It is of a bright 

 yellowish-tawny colour above, varied with blackish; white below, 

 with a line of the same colour in the fold of the groins. Legs brown. 

 Tail reddish above at its origin, gray below, and black at the tip. 



Length from nose to tail about 1 foot 2 inches; of the tail, near 

 15 inches; of the ears, 3 inches. 



Jumping Hare (Pcdetes Capeiais). 



It is a native of the Cape of Good Hope, where it sleeps during the 

 day, going forth by night, and leaping twenty or thirty feet at a bound. 

 It eats sitting nearly upright, with the hind legs extended horizontally, 

 and using the small fore feet to bring the food to its mouth. It is a 

 very strong animal, and with these same fore feet, which are admirably 

 formed for digging, burrows so expeditiously as quickly to hide itself. 

 It sleeps in a sitting position, placing the head between the legs, and 

 holding its ears over its eyes with its fore legs. 



Tail moderate or short. Sand and Mole Rats. Pouched. 



The genera Saocopliorus, Kuhl ; Pseudostoma, Say ; Geomys and 

 Kplostoma, Rafinesque ; Ascomys, Lichtenstein ; and Saccomys, F. 

 Cuvier, are given by Dr. Fischer as synonymous; and indeed the 

 distinctions, except perhaps in the case of Geomys and Diplostoma, do 

 not appear to be sufficiently marked to warrant their separation. 



Sir John Richardson remarks that M. Rafinesque-Smaltz, in 1817, 

 founded his genus Geomys on the Hamster of Georgia (Geomys pinetis), 

 described by Mitchell, Anderson, Meares, and others ; and referred tn 

 it, as a second species, the Canada Pouched Rat (Mus bwsarius of 

 Shaw). Under another genus, Diplostoma, he arranged some Louisiana 

 or Missouri animals, known to the Canadian voyagers by the appellation 

 of Gauffres, and remarkable for their large cheek-pouches, which open 

 forwards exterior to the mouth and incisors, to which they form a 

 kind of hood. These two genera, he observes, have been adopted by 

 few naturalists ; and the American systematic writers have either over- 

 looked M. Rafiuesque's species entirely, or referred them all to M. bur- 

 itiriut. In the latter case, Sir John says, they are undoubtedly wrong ; 

 for there are at least six or seven distinct species belonging to one or 

 other of these genera which inhabit America, and he thinks that both 

 Geomys and Diplostoma will eventually prove to be good genera; tho 

 Sand-Rats belonging to the former having cheek-pouches which are 

 filled from within the mouth, and the Gauffres, or Camas-Rats. of tho 

 latter genus, having their cheek-pouches exterior to the mouth, and 

 entirely unconnected with its cavity. Sir John Richardson had no 

 opportunity of examining Qeomys pinetis, the type of the genus, but 

 he had inspected an undescribed species from Cadadaguios, and another 

 (Geomys Douglasii) from the banks of the Columbia ; from these two 

 Sir John Richardson's characters of the genus were drawn up. With 

 regard to the Canada Pouched-Rat, great doubt, he observes, still 

 exists as to whether it belongs properly to Geomya or to Diplostoma. 

 Judging from the description of Dr. Shaw and the figure iu ' Linn. 

 Trans.' (vol. v. pL 8), Sir John Richardson has little doubt of the 

 cheek-pouches opening into the mouth, and of their being precisely 

 similar in form and functions to the cheek-pouches of the Sand-Rats ; 

 but he states that he was told, on good authority, that the identical 

 specimen described by Shaw (which at the sale of Bullock's museum 

 passed into the hands of M. Temrniuck), is in fact similar to the 

 Gauffres in having cheek-pouches that open exteriorly, and that conse- 

 quently Major Davies's drawing represented them in an unnatural and 

 inverted position. Mr. Say gives the characters of a Missouri Gauffre 

 with cheek-pouches opening exteriorly, and he identifies his specimen 



