354 DIDELPHTID*. 



6- 



d (in spirit). 



Adult. 



mUlim. 



Head and body 95 



TaU 119 



Lower leg 27 



Hind foot 14-5 



Muzzle to eye 13 



Ear 17 



SkuU, see p. 351. 



Sab. South. Brazil and Chili. 

 Ti/;pe in collection. 



I Ad. St. I Aconcagua, Chili. Mr. T. Bridges [C.]. 



■ I Skulls. I 



d. Ad. al., (J . Aconcagua. Mr. T. Bridges [C.]. 



e. Ad. sk., t? . 'Valparaiso (C. Darwin, Zool. Soc. (Voy. ' Beagle '). 



Mq.). (rj(pe of species.) 



/, g. Ad. sks., <S Valparaiso (C Darwin, Zool. Soc. (Voy. ' Beagle '). 



Esq). 



A. Skull. Vakiaraiso (C. JJajmre, Zool. Soc. (Voy, 'Beagle'). 



Esq.). (Figured by Waterhouse, Voy. 'Beagle.') 



i,j. Skeletons. OhiU. Mr. T. Bridges [0.]. 



k. Skull. ChiU. Mr. T. Bridges [C.]. 



V. Subgenus PERAMTS. 



Type. 

 Peramys, Less. N. TaU. S. A., Mamm. p. 187 (1842) D. brevicaudata. 

 Hemiurus, Oerv. Castehh. Amir. Sud, Mamm, p. 101 



■ (1855) D. brevicaudata. 



Microdelphys, Burm. Erliiut. Fawn. Bras. p. 83(1856) D. americana. 



Size small. Tail short, generally about half the length of the 

 head and body, more or less covered with fine short hairs, but little, 

 or not at all, prehensile. Fifth hind toe considerably shorter than 

 the second ; third and fourth but little longer than the second, sub- 

 equal. 



Skull very variable in size and shape ; generally broad, rounded, 

 and flattened above. Palate without a second posterior pair of 

 vacuities. 



Teeth. Upper p.' not disproportionally smaller than the others, 

 the upper premolars generally evenly increasing in size backwards. 

 Lower p.* generally larger than, but sometimes only just equalling, 



This subgenus forms a very natural group, and might almost be 

 admitted to generic rank, were it not that certain species of other 

 subgenera — as, for example, D. (Micoureus) velutina — approach it in 

 shortness of tail, and that neither in skuU nor dentition does there 

 appear to be any single character absolutely peculiar to it. 



The habits of the species are as yet undescribed, but they are 

 probably far less arboreal than the other Opossums. 



