ON THE GENUS PHASCOLOGALE 503 
and Chetocercus, Krefft (Dasycercus, Peters), cannot stand as 
distinct from it, their distinguishing characters, both cranial and 
external, being led up to or possessed by the different species in 
different degrees ('). On the other hand Sménthopsis, Thos. (?), 
and Antechinomys, Krefft, differ from Phascologale by such marked 
external characters that, although their skulls and teeth are 
in no way generically distinguishable from those of that genus, 
they should unquestionably be retained as distinct. 
The greater part of the species are here noticed, but some 
of the smaller and obscurer ones have been so badly described 
that I have not as yet been able to make them properly out. 
These, however, belong exclusively to the group Aniechinus, all 
those of the restricted Phascologale of the older authors being 
therefore included. 3 
The most important point in the description of the teeth has 
been found in the very remarkable series of gradations in the 
development of the last premolar, or pm + of the typical mam- 
malian series, and for convenience of description I propose to 
use the following scale: when the tooth is as large as or larger 
than pm + it is called of the size 3, when about the size of or 
slightly smaller than the anterior premolar it is called 2, and 
when quite minute 1. Thus in the common species Ph. penicil- 
lata it is of the size 3 above and 2 below, or è, while in Ph. 
apicalis it is minute both above and below, or =. 
The measurements of ali the species are placed together on 
p. 511. Those only however, which are taken from spirit spe- 
cimens can be trusted other than approximately. In the de- 
scriptions of the species also the combined lengths of the first 
three molars is recorded, this being apparently by far the most 
important measurement for descriptive purposes and its range 
(‘) When Mr. E. R. Alston wrote his excellent paper on Antechinomys (P. Z. S. 
1880, p. 460) such synthetic species as Phase. dorsalis, doriae, apicalis or virginice 
were either not known at all or had not had their dentition properly described. 
(®) From opivOog, a mouse, and Ste, appearance. New name for Podabrus, 
Gould, 1845, nec (Fisch. de Waldh.) Westwood, Introd. Ins. II. Synops. p. 27, 1840 
(Telephoridae). 
