BY R. BROOM. 



55 



PSEUDOCHIRUS ANTIQUUS 11. Sp. 



(PI VII. Figs. 4-6). 



One of the comiiioiiest forms whose remains are found in the 

 deposit is a species of Pseudochirios. In size and structure it 

 much resembles the common ring-tailed Phalanger (P. j^eregritius), 

 but the careful study of a large series of specimens has satisfied 

 me that the remains are those of a distinct and new species. In 

 average size the teeth are appreciably larger than in P. pei-egrinus, 

 yet on the whole the form comes nearer to that species than to 

 either P. cuoki or P. orientalis. 



The following table illustrates the features so far as known and 

 the points distinguishing the fossil form from P. pereyrimcs. 



P. perey7-iniis. 



Upper p^ small, about 1 mm. 



in front of p'^ 

 Length of m ^ -m ^ — 11 -2- 1 2 6 



mm. 



Cusps of upper and lower molars 



moderately developed 

 Post. Ext. Cusp of upper ra'^ 



(4 sp. ) mill. 1-7, max. 2*0, 



average 1"85 



Ant. Int. Cusp of lower m* 



(3 sp.) min 1-6, max. 1-8, 



average 1-7 



Palate with a distinct lateral 



depression in region of p^ 



and p* 



Angle of jaw produced well 

 backwards. 



P. antiquus. 



Upper p^ moderate size, j)laced 

 close to p'^ 



m^-m'^ in only three specimens, 

 showing complete series — - 

 12.7, 12-9, and 13- mm. 



Cusps of upper and lower molars 

 well developed 



Post. Ext. Cusp of upper m^ 

 (5 sp ) min. 2-1, max. 2-3, 

 average 2 -2 2 



Ant. Int. Cusp of lower m^ 



(3 sp.) min. 2-3, max. 2 5, 



average 2*4 



Palate moderately flat, no dis- 

 tinct lateral depression in 

 region of p'^ and p* 



Angle of jaw relatively small 

 and passing backwards but 

 a short distance 



