Mr. J. Gould on Semioptera Wallacii. 75 



Length of the head and body, about 3 6 



of the tail, about 3 



of the head 1 5 



Hab. Gualaquiza. Collected by Mr. Fraser, Dec. 1857. 



Obs. — This species was first described by Mr. Waterhouse in his 

 excellent work on * Mammalia' *, but without a name, and was com- 

 pared with D. cinerea, from which it was observed to differ in having 

 the hairy portion of the tail of much less extent, in having longer 

 fur, and in being itself considerably smaller. The specimen examined 

 was a male, and included in that section of Opossums characterized 

 by a pouch "rudimentary or entirely wanting;" but the female 

 obtained by Mr. Fraser (evidently of the same species) unquestion- 

 ably possessed a complete pouch, as might be seen from an examina- 

 tiyn of the skin preserved in spirit ; and Mr. Fraser' s note accom- 

 panying the specimen informs us that there were " five young in her 

 pouch, each 3 inches long." 



This effectually disposes of the question as to its distinctness from 

 D. cinerea, and in fact removes it to the other section. 



To D. noctivaga, Tschudi, it bears some resemblance, in which 

 species, as in D. Waterhousii, the fur on the base of the tail is of ex- 

 ceedingly limited extent, and both agree in having rather long fur, 

 although of a different colour. But B. noctivaga is the larger species 

 of the two, and is quite differently proportioned. Its muzzle is a 

 great deal longer than that of D. Waterhousii, and the ears are much 

 larger. Moreover the female is destitute of a pouch, and has in its 

 stead " abdominal folds of the integuments." The eyes too, accord- 

 ing to Dr. Tschudi's figure and Mr. Fraser's note, are of a different 

 colour. 



Mr. Fraser's note in full is as follows : — " $ had five young in 

 her pouch, each 3 inches long. Nose, chin, and latter half of the 

 tail flesh-colour ; ears black. Stomach contained bones of a small 

 mammal, hair, and a pulp containing a vegetable substance. Eyes 

 black. Xivaro name ' Juichma* " 



I have named this animal after its original describer, as a tribute 

 to a zoologist who has in such an eminent degree extended our know- 

 ledge in this branch of natural history. 



Notes on Semioptera Wallacii, Gray, from a Letter 

 addressed to john gould, esq., f.r.s., by a. r. wal- 

 LACE, Esq., dated Amboyna, Sept. 30, 1859. 



" The Semioptera Wallacii frequents the lower trees of the virgin 

 forests, and is almost constantly in motion. It flies from branch to 

 branch, and clings to the twigs and even to the vertical smooth 

 trunks almost as easily as a Woodpecker. It continually utters a 

 harsh croaking cry, something between that of Paradisea apoda and 

 the more musical cry of Cicinnurus regius. The males, at short 



* vol. i. p. 505. 



