i 
Mr. J. Gould on Semioptera Wallacii. 75 
Length of the head and body, about ...... 3 6 
OLine teal. about. .. <:..sclaessasie, oo OD 
of the head ......... - Tes GE: 
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 D. noctivagais the larger species 
of the two, and is quite differently proportioned. Its muzzle is a 
great deal longer than that of D. Waterhousit, and the ears are much 
. 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 :—‘ 2 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 SemiopTerRaA Wa.xuacii, GRAY, FROM A LETTER 
ADDRESSED TO JoHN GouLp, Esa., F.R.S., py A. R. Wat- 
LACE, Esa., 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. 
