MAMMALIA RODENTIA. 267 



unites forsooth not merely Poephagomys, but even Octodon and Schisodoii, 

 with Ctenomys, thus bringing together genera the most different ; in doing 

 this lie would leave it as an undecided point whether they may not be 

 regarded as forming a small family or a single genus. Eversmann remarks 

 in the ' Bullet, de Petersb.' ii, p. 124, that Ellobius talpinus occurs in the 

 fertile steppes on the south-western promontories of the Ural in frequently 

 incredible numbers. 



MUEINA. It has been found that the geographical distribution of Nus 

 mmutus extends much further north than has hitherto been supposed. 

 Suudevall alludes to W. v. Wright, upon his late return from a journey to 

 Finland, having found the Mus miuutus in the country of Kuopio, upon 

 which Hornschuch observes, that it occurs also not unfrequeutly in Neu- 

 Vorpommem. (Archiv. skaud. Beitr. z. Naturgcsch. I. S. 140.) Of 

 Cficetomt/s yambianus Eraser remarks, that it is common upon the Island 

 of Fernando Po, lives under the ground, but ascends also trees to get at 

 their fruit, and with the natives is regarded as the greatest delicacy on 

 high days or holidays. (Ann. Nat. Hist, xiii, p. 225.) Bridges sets 

 down some short remarks concerning the habits of Hesperomys lonyicaudatus 

 and longipilis. (Aim. Nat. Hist, xiv, p. 53.) The Swedish Lemmings 

 (Lemmus, Geoffr.) are arranged by Nilssou in the following manner. 

 (Archiv. Skand. Beitr. i. S. 146.) 



a. All the grooves of the molar teeth disposed in a zigzag manner. 



1. HypudiSKs : the most median molar tooth having above three lateral 

 and externally directed ridges, with two still larger ones inwardly, without 

 a trace of a third. They divide into a. Earth-rats ; all three above-mentioned 

 lateral ridges very large and acutely angular : here belong Lemnus ampldbius, 

 Linn., and L. medius, Nilss. (3. Earth-mice; the most anterior and external 

 lateral ridge upon the selfsame tooth much smaller than that upon the others. 

 Ex. L. glareola and rutilus. 



2. Anicola : middlemost molar having above three lateral ridges exter- 

 nally, three internally, of which two are of the same size as the outer ones, 

 the third being much smaller : here belong L. insularis, Nilss. and L. agrestis, 

 Linn. Arvicola arvalis has never been found as yet in Sweden, but belongs, 

 by virtue of the middle superior molar tooth, to this subdivision. 



b. Grooves of the posterior molar nearly parallel, those of the remainder 

 in zigzag. 



3. Myodes ; tail very short, about half the length of the head, being 

 shorter or equal in length to the hind foot : here belong L. iiorveyicus, Nilss., 

 and L. schisticolor, Lilj. 



Nilssou characterizes his Lemnus medius, S. 146, in the following manner : 

 similar to L. agrestis but somewhat larger, and of a dark colour, with a 

 somewhat longer tail, and wholly devoid the posterior small supernumerary 

 enamel folds upon the middlemost upper molar. From Lapland and the 



