36 



CLASS MAMMALIA. 



ORDER R O D E N T I A. 



and generally but little covered with hair ; front feet four-toed with a rudi- 

 mental thumb, hind feet five-toed ; claws falcular. 



6. DIPUS (Gr. Kt, twice, and irowc, afoot). Two incisive teeth in each 

 jaw; head broad; eyes prominent and large; hind legs very long; hair 

 long, and tufted at the extremity. 



7. PEDETES (Lat. pes, a foot). Incisive teeth two in each jaw, smooth 

 in front, chisel-shaped, those of the lower jaw truncated and not pointed ; 

 molar four on a side in both jaws, their crowns rather cylindrical, sur- 

 rounded by a circle of enamel, divided into two halves by a groove ; head 

 broad, and flat between the ears ; muzzle obtuse, and terminating in a very 

 short nose, in which the nasal openings appear as two clefts ; upper lip 

 entire, the edge joining on each side behind the incisive teeth so as to form 

 a kind of pouch ; whiskers very large and strong ; ears long, narrow, and 

 pointed ; eyes large and low ; fore legs short, and having five distinct toes, 

 tipped with long, narrow nails, grooved, and fit for digging ; hind legs very 

 long, four-toed, the outermost toe the shortest and the inner the longest, 

 the others of equal length, and all armed with very thick, straight, tri- 

 angular, and pointed nails ; tail long, very thick, and muscular, and entirely 

 covered with longish hairs ; four pectoral teats ; and in the female an 

 abdominal pouch, as in the Opossum, but not containing the teats. 



8. ARCTOMTS (Gr. fiprroc, a Bear, and fivt, o. Eat). Two strong, 

 sharp, wedge-shaped incisor teeth in each jaw ; five tuberculated grinders 

 on either side in the upper, and four in the lower jaw. 



9. FIBER. Incisive teeth covered by the lips ; six molars in each jaw ; 

 muzzle short and obtuse ; ears hidden ; tail long, flattened, and scaly ; toes 

 distinct, those of the hind feet increased in breadth by a lateral membrane ; 

 claws much hooked. 



10. MERIONES (Gr. fiypot, a thigh). Incisive teeth two in each jaw; 

 the front of the upper marked with a longitudinal groove ; no cuspid ; 

 molar tritorial ; nose sharp ; lip cleft ; ears not half so long as the head ; 

 tail moderate size, slightly ringed, covered with close hair ; fore legs short, 

 four-toed, hind legs three times as long as the fore, five-toed ; claws mode- 

 rate, fit for digging. 



11. MTOPOTAMUS (Gr. ftvf a Mouse, and irorafioc, a river). Head 

 large, muzzle obtuse; ears small and rounded, incisive teeth large and 

 tinged with yellow ; molar compound, four in each side in both jaws ; tail 

 long, conical, strong, scaly, and slightly covered with hair ; feet five-toed, 

 the thumb of the fore feet very short, the other toes unconnected ; hind feet 

 webbed. 



12. ONDATRA. Incisive teeth large, the upper flatly rounded in front; 

 the lower chisel-shaped, and nearly pointed at the tip ; molar four on a side 

 in either jaw ; nose short, thick, and obtuse ; eyes small, lateral, much 

 hidden in fur ; ears short, hairy, and scarcely distinguishable ; body thick, 

 flattish, covered with a long pile and close down ; tail compressed laterally, 

 and of nearly equal length with the body ; thighs hidden in the body ; feet 

 five-toed ; hind feet very large, toes distinct ; middle two united by web ; 

 claws large, thin, slightly arched, and conical. 



13. SACCOMYS (Gr. awcKOf, a pouch, and /*vc, a Mouse). Incisive teeth 

 chisel-shaped, two in each jaw ; molar four on a side in either jaw ; muzzle 

 obtuse, upper lip cleft ; cheek-pouches external to the mouth, and opening 

 downwards ; auricles large and elliptical ; body short and covered with long 

 silky hair ; tail slender, long, and covered with verticillated square scales ; 

 feet five-toed ; claws short, sharp, and compressed, excepting those of the 

 thumbs of the fore and the second toe of the hind feet, which are straighter, 

 wider, and flatter. 



14. SACCOPHORUS (Gr. OUKKOC, a pouch, and <f>tp<a, to bear). Incisive 

 teeth two in each jaw, uncovered by the lips, chisel-shaped ; molar, five on 

 a side above, inclining obliquely backwards, and four below inclining for- 

 wards ; head and trunk bulky ; eyes small ; ears short ; cheek-pouches very 

 large, unconnected with the mouth, but opening downwards and towards 

 it ; legs short ; feet five-toed, the front claws very long and much curved, 

 hind claws short ; tail of variable length. 



15. SCIUBUS (Gr. arta, a shadow, and oipa, a tail). Incisive teeth 

 two above, the upper with the front surface smooth, the lower much com- 



pressed ; molar teeth four on a side in either jaw, tubercular, and in the 

 upper a fifth, which is very early deciduous ; muzzle sharp, and upper lip 

 cleft ; eyes large and lively ; ears oblong, sometimes tufted ; tail distichous, 

 or dichotomous, t. e. disposed in two rows like the barbs of a quill, or 

 cylindrical ; hind much longer than fore limbs ; feet ambulatory, the anterior 

 four-toed, with a tubercle in place of thumb, sometimes covered with A 

 broad nail, the posterior five-toed ; all the nails clawed. 



16. SPERMOPHILUS (Gr. airtppa, a seed, and </>l\oe, one who loves). In- 

 cisive teeth chisel-shaped, two in each jaw ; molar teeth five on a side above 

 and four below ; cheek-pouches ; pupils oblong and vertical ; auricles small 

 and close to the head, their margins curled inwards towards the auditory 

 passage ; tail short, often distichous ; legs long, with distinctly-divided toes. 



17. TAMIAS (Gr. rapae, a storekeeper). Incisive teeth two in each 

 jaw ; molar teeth four on a side in each jaw, and in the upper a fifth very 

 small, rudimentary, and early deciduous ; profile of the whole head curved 

 and regular ; cerebral cavity not occupying half the head ; face narrow ; 

 muzzle sharp and upper lip cleft ; large cheek-pouches ; tail roundish, com- 

 pletely hairy, and as long as the body ; feet four-toed in front, five-toed 

 behind, and their claws not pointed. 



CLAVICtTLATA. DESCRIPTION OF THE SPECIES. 



HYPOTXEUS CampagncH. This genus has been separated from the Lin- 

 na?an genus Mus by Pallas ; the animals are wild, and live in holes which 

 they burrow in the ground. Some of them are natives of England, but the 

 most destructive are found only in northern regions. 



The species are the Water Rat (H. Amphibius), about seven inches 

 long ; body covered with long black hairs, intermixed with reddish ; belly 

 iron grey ; tail five inches long, covered with short hair. It lives on the 

 banks of rivers in holes, which it digs in search of roots, on which it feeds. 



The Meadow Mouse (H. Arvalis), which is about six inches long. These 

 animals live in companies on high and dry lands, in burrows about six 

 inches from the surface, and divided into several apartments, from which 

 the pregnant female sinks a hole of two or three feet in depth, terminating 

 in a chamber about the size of a man's fist, which she lines with dry grass, 

 and in it drops six or eight young at a birth. It is common in England, 

 and in France is a very severe scourge, not only devouring the seed as soon 

 as sown, but destroying it during every period of its growth. 



The Economic Rat (H. (Economus), so called from its habit of storing 

 up food for the winter, is rather more than four inches long ; is a native of 

 Siberia and Kamtschatka, and said to be found occasionally in Switzerland 

 and France. These Campagnoles present an instance of migration, but at 

 uncertain periods ; and the immensity of their numbers may be in some 

 degree estimated, when it is stated, that travellers have been detained for 

 two hours whilst the little four-footed army passed by. 



We pass over the Social Campagiwl (H. Gregalis), found in Siberia ; the 

 Garlic Campagnol (H. Alliarius), a frequenter of the rivers Lena and Jenesei ; 

 the Red Campagnol (H. Rutilus), of Siberia ; the Rock Campagnd (H. 

 Saxatilis), found in the Mongolian Desert, and proceed to give a brief notice 

 of the Lemmus, a representation of which is contained in Plate 12. This 

 animal (H. Lemmus) is about the size of our common Rat, and is covered 

 with a very thin skin, the fur of which on the head and back is black and 

 tawny, disposed in irregular patches, and the belly white tinged witli yellow ; 

 its tail is not above half an inch in length. It inhabits Norway and Lap- 

 land, the country about the river Oby, and the northern part of the Uralian 

 chain. It makes its appearance in these countries at irregular periods, 

 sometimes after an interval of three years. It is probable that they migrate 

 in consequence of want of food, and as they proceed they destroy every- 

 thing, leaving a perfect waste behind them. Nothing stops their progress, 

 neither rocks nor water ; the former they compass, the latter they swim 

 across, and although destroyed by thousands by the predacoous animals, 

 more especially the Arctic Fox, they journey onwards in an unbroken and 

 devouring mass. They move principally by night, and rest during the day. 



MYOXUS Dormouse. The Dormice arc of an elegant form, and much 

 resemble the Mures in their appearance. They feed on all kinds of fruit, 



