MAMMALIA KODENTIA. 41 



than ours no great superabundance in this respect exists. Now, I am very 

 averse from seeking to deduce general laws from single, isolated observa- 

 tions, seeing that the greatest mistakes may thus arise, inasmuch as Bur- 

 meister liimself has fallen into one of this kind. I have, for instance, from 

 the inspection of the skeletons set up in our collection, of Mi/odes Lemnms 

 and groenlandicus, Hypudeeus, amphibius, terrestris, atyinus, and hypoleucos, 

 ascertained that the above-mentioned elongation of the spinous process is 

 entirely wanting in all of them, in which all these processes are in general 

 very short. Consequently, on account of such a trifling character, pro- 

 bably all the Arvicoliua would be excluded from the Mouse family, which 

 would be highly unnatural, especially as in this respect .one does not know 

 whether other genera may not go with them. Other of the charac- 

 ters, also, assigned by Burmeister to the Mice, such as " rounded, more or 

 less naked ears, scaled or setose tails with hair between, five toes before and 

 behind," are not generally valid, although I had also inadvertently admitted 

 the two latter characters in the definition of- the family. 



Five new species of the gemis Mus, from New Holland, 

 have been published. 



Three of them by Gould (Ann. Nat. Hist, x, p. 405), viz. (1) Mus peni- 

 cillatus. " Griseo-fuscus, vellerc fere ut in M. decumano ; corpore subtus 

 pedibusquc albis flavo lavatis ; auribus mediocribus, postice subemargiuatis ; 

 cauda gracili, dimidia apicali pilis longis uigris vestita." Body 7" 3"', tail 

 7" 9'". (2) M. hirsutm. " Vellere hirsute, corpore supra fuscesccnte pilis 

 uigris crebre commixtis, subtus fulvescens, fusco rufoque tiiicto ; auribus 

 mediocribus ; cauda louga pilis nigris, aliquauto longis, vestita, dimidia 

 apicali pilis lougioribus, his ad apicem caudse rufesceutibus." Body 10" 4'", 

 tail 13". (3) M. delicatulus. " Supra pallide fusco-flavus ; corpore ad 

 latera flavesceute subtus albo ; cauda mediocri supra fusca, subtus ad basin 

 albescenti ; auribus parvulis ; pcdibus gracilibus albis." Body 2" 5'", 

 tail 2" 2"'. 



Waterhouse's two species are (Ann. Nat. Hist, xii, p. 13i) : (1) Mus 

 ritxtancm. " Intense castaneus, corpore subtus pallidiore ; cauda corpore cum 

 capite longiore ; auribus mediocribus." Body 2" T" , tail 3". (2) M. Nova; 

 Holla >id UP (a very badly chosen name). "Supra canus flavescente lavatus ; 

 corpore subtus pedibusque albis ; auribus mediocribus ; cauda quoad longi- 

 tudiuem corpus fere requante." Body 3", tail 2". 



As species introduced into New York, De Kay (Nat. 

 Hist, of New York. Mamm. p. 79) mentions Mus decumanus, 

 rut/us and musculus ; as a new species he describes Mus 

 aiiic'ricanus. 



"Black above, lead-coloured beneath, cars longer than wide, tail shorter 





Y 



