1894.] DIDELPHTIDiE OF S.E. BRAZIL. 465 



have had moments when I became doubtful whether the P. henseli, 

 a second new Peramys of South Bi'azil, recently described by Mr. O. 

 Thomas, and figured on the same plate, might not also be such a 

 pale-striped individual of P. tristriatus. Burmeister's figure of 

 P. tristriattis (pi. xvi. tig. 2) I consider deficient in regard to several 

 points. 



Peramys tristriatvs, not at all a " rare animal," as is stated by 

 Burmeister (Syst. Ueb. p. 141), inhabits localities more or less 

 similar to those of Micoureus pusUhis. It is often seen in forest- 

 paths, especially in the neighbourhood of water. When in 1891 we 

 dug a deep channel for our savviug-engine, this channel running 

 about a kilometre through the forest, nearly every day a Peramys was 

 found in it, and even now the Mater often brings down some indi- 

 vidual specimen of this marsupial. It is entirely terrestrial, and 

 for arboreal life it is improperly built. 



I also know Peramys tristriatus quite well as concerns its habits 

 and character, from studying captured specimens. Its food in free- 

 dom is similar to that of Micoureus pusillus ; but I learned that it 

 attacks comparatively larger animals than the former, and assails 

 without hesitation birds and mammals nearly as large as itself. I 

 was once imprudent enough to put together in the same cage an 

 adult Peramys and a young Hesperomys squamipes. The next 

 morning I found nothing more of the latter than a small piece of 

 the skin, and the cage soiled with undeniable traces of a terrible 

 combat. The disposition of this species is not nearly so attractive as 

 that of Micoureus piisill us ; bloodthii'stiness and a blind delight in 

 cruelty are the prevailing features, and a low degree of intelligence 

 renders taming a very ungrateful matter. An almost stupid restless- 

 ness and unbounded fondness for hberty, together with an unsa- 

 tiable need of food, are generally the causes of a wonderfully rapid 

 decay and death. Young individuals, bow ever, are pleasing creatures, 

 remarkable for their large beads. With milk and insects they 

 can be kept alive some time by persons having the necessary time 

 and leisure. I know here of a person who observed the copulation 

 of Peramys, and was once told of a mother carrying her young on 

 her back ; unfortunately I arrived too late to see it. 



It is also necessary to say that the habits of Peramys are equally 

 by preference nocturnal. 



The measurements of three individuals before me are : — 



a. $ (spirit pres.) total length 157 mm., head and body 105 mm. 



b. cS (dry skin) „ ,, 179 mm. „ „ 120 mm. 



c. c5' ( » ) „ „ 201 mm. „ „ 145 mm. 

 The basilar length of the skull of specimen b is 28-5 mm., of 



specimen c 28 mm. (Mr. O. Thomas mentions for an adult d" of 

 P. americana 28 mm., for an adult (?) ' cJ of P. iheringii 22*2 mm.). 



6. Chieonectes palmatus. 



The singular and beautiful Water-Opossum, so well represented 



^ [This query is Dr. Goeldi's, not mine. — O. T.] 



