hitherto referred to " Mus.' 



605 



Australian and Papuan species : — 



arboricola, Rams. ( = rattus). 



assimilis, Gould. 



brotcni, Alst. 



colletti, Thos. 



culmorum, Thos. & Dollm. 



e.rulans, Peale. 



fuscipes, Waterh. 



gestri, Thos. 



grei/i, Gray. 



lutreola, Gray. 



manicatus, Gould. 



maorium, Hutt. 

 mordav, Thos. 

 jjrcetor, Thos. 

 sordidus, Gould. 

 terrce-regince, Alst. 

 tunneyi, Thos. 

 vel/erosus, Gray. 

 velutinuv, Thos. 

 villosissimus, Waite. 

 woodioardi, Thos. 



Pseudomys, Gray. 

 P. Z. S. 1832, p. 39. 



Size variable, mostly much smaller than in Epimys. 

 Pectoral mamma? not known to be present in any species, 

 the formula being — 2 = 4 in all in which it can be deter- 

 mined. 



Skull not heavily built and quite without supraorbital 

 ridges; the interorbital region narrow, parallel-sided, with 

 rounded or, in a few species, squared edges. Front edge 

 of zygomatic plate, structure of pterygoid region and of 

 molars, varying in the different subgenera. 



Range. Australia and Tasmania, not extending into New 

 Guinea. 



Type. Pseudomys auslralis, Gray. 



This genus contains species of very varied skull and molar 

 structure, and it is with some hesitation that I leave such 

 diverse species as, for example, P. australis and P. forresti 

 under the same generic heading. But as the characters, 

 marked as they are in extreme cases, seem to be slighter or 

 variable in others, I think the division of Pseudomys into 

 subgenera may best serve our present purpose. 



Of these there would be four, as follows : — 



1. Pseudomys, s. s. 



Size large. General form of skull inclining towards that 

 of Conilurus and Leporillus by the flat or even concave con- 

 dition of the posterior nasal region and the bold projection of 

 the anterior part of the zygomata. Front edge of zygomatic 

 plate concave, with a projecting point above, as in Noto/nys, 

 though not so strongly marked. Palatal foramina large. 

 Pterygoid region showing an intermediate condition between 

 the normal one and the flattened state described below under 



