629 



MURID^E. 



930 



Lac<5p.), which he subdivides into 1st, the Ondatras (Fiber, Cuv.) 

 and, 2nd, the ordinary Campagnols (Arvicola, Cuv. ; Hypudaus, II!. 

 the Lemmings, Cuv. (Georychus, 111. ; Otomys, F. Cuv.), and the 

 Jerboas (Dlput, Gin.). To these succeed the Jumping Hares (Hdamys 

 F. Cuv.; Pedetes, III), the Mole-Rats (Spalax, Quid.), the Orycteres 

 F. CUT. (Bathyeryus, 111.), Geomys, Raf. (Pseudostoma, Say, Ascomys, 

 Licht., Saccomys ( ? ), F. CUT.), and Diplostoma, Raf. 



Dr. J. E. Gray, in his ' Outline' (' Ann. PhiL,' 1825), after observing 

 that the Gllret are' exceedingly difficult to arrange, and that the 

 arrangement given is only " an attempt according to their habits," 

 makes Muridte the first family of the order, with the following 

 character : " Cutting teeth two in each jaw, lower awl-shaped, 

 grinders simple orcompound.upper shelving backwards, lower forwards ; 

 limbs proportionate, tail scaly, fur with scattered longer hair?, or flat 

 spines ; clavicles distinct." 



He then subdivides the family as follows : 



+ Grinders rooted, simple. 



1. Murina. J/iw, Liun. ; Otomys, F. Cuv. ; Capromyi, Desm. 



2. Jfydromina. Bydromys, Geoff. 



ft Grinders rootless, compound. 



3. Ondatrina. Ondatra. 



4. C'tutorina. Caitor, Linn. ; Osteopora, Harlan. 



^ 5. Echymina. Echymyt, Geoff. ; Jleteromyg, Desm. ; Saccomys, F. 

 CUT. In the ' Catalogue of specimens in the British Museum,' Dr. J. E. 

 Gray has somewhat modified this arrangement. A list of the British 

 Museum specimens of this family is given at the end of this article. 



Dr. Fischer, in his 'Conspectus Ordinum et Oenerum ' (1829), divides 

 the Glira into two sections : the first consisting of those with complete 

 clavicles ; and the second of those which have none. The following 

 genera are thus arranged under the first section : Castor, Lemmus, 

 Spalaj-, Saccophorui, Loncherei, Myoxut, Bydromys, Capromys, Mus, 

 Cricetuf, Saccomys, Pedeta, Diput, Aulacodus, Arctomys, Sciurus, 

 Pteramyt, and Chelromya. 



Mr. Swainson, in his ' Classification of Quadrupeds' (1835), also 

 separates the Glira into two divisions: the first, or Olira proper, 

 with clavicles ; and the second with rudimentary clavicles, or none. 

 In the first division, after the genera C'attor, Fiber, and Myopotamm, 

 and an observation in a note to the first section, that these divisions 

 are purely artificial, and merely formed to facilitate the search among 

 BO many unarranged groups, we find the following sections : 



1. Rats and Mice, under which are arranged the following : 

 Arricola, Lac<?p. (llypudaui. 111.). Example, Mus amphibius. Linn., 

 Water-Rat, Penn. ; Gcoryckia, 111. (Lemmings). Example, Mus Nor- 

 regicut, Linn., the Lemming.* Bcldmyt, Geoff. (Spined Rats). Ex. 

 Echimyt crutatus, Desm., Gilt-Tailed Dormouse, Penn. Myoxus, Gin. 

 (Dormouse). Ex. Mat artllanariua, Linn., the Common Dormouse. 

 Hydromys, Geoff. (Water-Rat). Ex. II. leucoyatler, Australia. Mus, 

 Auct. Ex. if. Rattut, Linn., Common Rat Capromyi, Desm. Ex. 

 C. prtheniilis. South America. C'ricelut, (Hamster). Ex. C. vulgaris, 

 the Hamster. 



2. Fore legs very short, bind legs long. Jumping Mice, under 

 which come the following genera and sub-genera : Dipus (Jerboa), 

 Ex. Mat Jaculus, Linn. (D. Sayitta, Dura.). Sub-genus Gerbillus, 

 Desm. Ex. St. Tamariicintu, Tamarisk Jerboa, Sh. Merionet, F. Cuv. 

 Ex. Merionet Labradoriut. Sub-genus Pedetes, III Ex. M. Cafer, 

 PalL, Cape Jerboa, Penn. Then follows Lagoslomui, Brookes, with 

 its sub-genera Chinchilla and Lagotis. [CHINCHILLJD.E.] 



'',. Tail very short. Mole and Sand-Rats, including Geomys, Schmaltz 

 (Sand-Rat). Ex. Geomyt Douglasii, America. Diplostoma, Schmaltz, 

 America; Aplodontia, Richardson. Ex., A. leporina, America. Aspalax, 

 UiiM.-h Ex. Mm TyjMui, Pall., Asia; Sathyenjus, III Ex. M. man- 

 tin* in. Gin.. Africa. 



4. Tail long, bushy. Squirrels, under which are arranged Arctomys, 



Geoff., and the genus L'htiromyt. 



The numerous forms which press upon the attention in considering 

 this large section of Mammalia are enough to convince any one who 

 ha* bestowed any thought on the subject that authors have not 

 spoken of the difficulties surrounding it without reason. AVe shall 

 therefore introduce the student to the most remarkable among them ; 

 and, adopting Mr. Swainson's names for the first three sections as 

 arbitrary divisions under which we may bring the structure and 

 habits, where they are known, of these animals before the reader, 

 proceed to examine the natural history of this great and destructive 

 group. 



Rats and Mice (popularly so called). 



Arvicola. Ears moderate. Muzzle obtuse. Anterior toes armed 

 with moderate claws. Tail round and hairy, not so long as the body. 

 Number of teats from 8 to 12. Molars composite, with flat crowns, 

 presenting angular enamelled laminae. 



f,'raryrltut It generally considered to signify the Molc-Rats. The true 

 Lemming*, such as Mus Xortegicut, are closely allied to Arvicola. 



t Aipalaz is Olivier'j name ; Spalax is GUldcnstadt's, 

 HAT. HMJT. DIT. VOL. I1L 



Dental Formula : -Incisors, -; Molars, 2 = ; 

 2 3 



Teeth of Arricola. F. Cuvier. 



Cuvier divides the great genus Arricola of Lac^pikle (Campaguols) 

 into the Ondatras (Fiber, Cuv.) [ONDATRA], and the Campagnola 

 Ordinaires (Arvicola, Cuv. ; ffypndceus, 111.) ; and so they stand in 

 Cuvier's last edition of the 'Regne Animal.' M. Lesson, in his 

 'Manuel,' states that Cuvier has formed two sub-divisions of the 

 Arvicola, namely, first, the Campagnols Nageurs, of which M. Lesson 

 gives A. amphibius, Desm., Mus amphibius, Linn., as an example ; 

 and second, the Campagnols Terrestres, which may be exemplified by 

 A. ayrestis. 



Adopting this latter sub-division of Arvicola iu its restricted sense 

 for convenience, there being hardly sufficient difference in the 

 structure, whatever there may be in habits, to justify the breaking 

 the true Arvicolce down into two groups, we shall, before we proceed 

 to the description of the two examples selected, detain the reader 

 very shortly with the views of two modern English naturalists of 

 note with respect to the Anicolw. 



Dr. Gray raises this group to the rank of a family under the name 

 of Arvicolidce, or of a tribe Armcolina, and under it places his genus 

 Ctenodactylus, a word, by the way, which comes very near to Dejean's 

 name for a genus of Coleopterous Insects, Ctenodactyla. [CTENO- 

 DACTYLUS ; CTENODACTYLA.] Mr. Yarrell is of opinion that C. Mas- 

 tonii of Gray, is, as suggested by Mr. Ogilby, identical with the Mus 

 Gundi of Rothman, on whose description is founded the Arctomys 

 Gundi of Gmelin and others, and the Gundi Marmot of Pennant's 

 ' Zoology.' 



Mr. Bell, in his ' British Quadrupeds,' observes that the location of 

 the Armcolce with the genus Mus involves an inconsistency which was 

 early detected, and the correction of which has been universally 

 recognised and followed. The characters of the teeth, he remarks, 

 as well as tbe general form of the body, and the habits of all the 

 species, remove them not only generically from the Mures, but even 

 point out their association with a different family of the Rodentia; 

 and their affinity to the beaver, he adds, appears to have forcibly 

 struck Liuncous himself, who, in his 'Fauna Suecica,' applied the 

 name Castor to the European Water-Vole, or Water-Rat. Mr. Bell 

 then continues thus : " The generic term Arvicola, if not absolutely 

 unobjectionable, must be retained, as having the sanction of priority 

 over the name Microtus of Schrauk, Hypudceus of Brant, or Lemmus 

 of F. Cuvier. With regard to the name of the family, I have ventured 

 to change that of Dr. Gray, Armcolida, to Castoridce, because the 

 ;enus Castor must be considered as the type of the family, of which 

 .he present can only be an aberrant form." [BEAVEB.] 



Section 1. Water or Swimming Arvicoles or Voles. 

 A. amphibius, Desm. Castor caudd lineari tereti (Linn. 'Faur. 

 Suec.'); Mus amphibius ('Syst. Nat.,' Mull., 'Zool. Dan. Prod.'); 

 M. aqualicus (Briss.) ; Lemmus aquaticus (F. Cuv.) ; Arvicola amphibia 

 Jenyns) ; A. aquatica, (Flem.) ; Rat d'Eau (13uffon) ; Water Rat 

 Pennant). 



The head is thick, short, and blunt; eyes small, not very prominent ; 

 ears short, scarcely conspicuous beyond the fur ; the cutting-teeth of 

 a deep yellow colour in front, very strong, chisel-shaped, considerably 

 esembling those of the beaver; the surface of the grinding-teeth 

 ormed of alternate triangles arranged on each side of the longitudinal 

 ixis ; fore feet with four complete toes, the last phalanx only of the 



3 o 



