414 



Mv. O. Thomas on nexn Tasmanian Muridai. 



fourth. Sole-pads five on the fore feet and six on t]ie hmd. 

 Mamma3 only four, there being no pectoral and only two 

 inguinal pairs ; these latter both quite close to the vulva. 

 Ca?cum large, about 3 inches in length. 



Skull and incisor teeth of ordinary murine proportions ; but 

 the molars most remarkably broad and heavy, the anterior 

 ones each more than half as broad again as the palatal space 

 between them. Their pattern also, as shown in the woodcut 

 (fig. 2), is somewhat different from that of true Mus^ as there 

 are three cusps to the middle lamina of the first and the ante- 

 rior lamina of the second tooth only.^ These third cusps, 



"which are external, are very small, while the internal ones are 

 unusually large. Third molars remarkably large, as long as 

 either of the preceding teeth. Front edge of the anterior 

 zygoma-root (woodcut, fig. 3) markedly concave. Anterior 

 palatine foramina very narrow, extending backwards to be- 

 tween the middle of the first molars. Supraorbital edges 

 ■without marked ridges. 



For dimensions see below. 



The type and only specimen of this interesting form is an 

 adult female in alcohol, presented to the Museum in 1852 by 

 Mr. Ronald Gunn. 



It is worthy of note that externally this rat is almost exactly 

 similar to the next species, an animal also from Tasmania, so 

 that an examination of the skull is needed to distinguish the 

 two forms. 



The second species is a member of the restricted genus 

 Ifws, and I propose to call it, on account of the velvety 

 nature of its fur, 



