XVII THE SLOW LORIS B45 
deposit of fat formed chiefly at the root of the tail, and intended 
to tide over the time of the creature’s hibernation. But, as a 
matter of fact, this peculiarity also exists in Chirogale. Of 
Opolemur but two species are known, and of one of these, named 
after Mr. Thomas of the British Museum, only three examples are 
in existence in museums, that is to say In one museum—our own 
at South Kensington. Many of these dwarf Lemurs are exceed- 
ingly rare. In this genus and in the last two the palate has a pair 
of posterior fenestrae, of which there are also traces in other Lemurs, 
but which are particularly large in Microcebus. This is, of course, 
a well-known character of the Marsupials, and also, which is more 
important in the present connexion, of certain Insectivores. 
Sub-Fam. 4. Lorisinae.—This sub-family is the only one with 
a wide distribution, and it contains, with the exception of Zarsius, 
the only Asiatic members of the group. Correlated with its 
wide distribution there is more divergence in anatomical characters 
than is the case with the other sub-families of the Lemuridae. 
In external features all the three genera of this sub-family agree 
in their small size, their short or entirely deficient tail, large 
staring eyes, and the rudimentary character, or absence, of the 
index finger, which is never provided with a nail; in all of them 
the thumb diverges widely from the other fingers, and the great 
toe is so divergent as to be directed backwards. In the brain 
there is one character common to all three genera, and that 1s 
the small length of the angular fissure. The caecum, which 1s 
long, is supported by three folds, of which the median is anangious, 
and is sometimes attached to the longer of the two lateral folds, 
which are vascular. The members of this sub-family have more 
dorsal vertebrae than are found in other Lemurs; the range 1s 
from fourteen in Loris, to sixteen in Nycticebus. 
The genus Vycticebus contains only a single species, V. tardi- 
gradus, though four other names have been given to supposed 
varieties. Moreover, the genus itself has been named Stenops, as 
also the next genus Loris. The body of this animal is stouter than 
that of the next to be described. Professor Mivart has pointed 
out that, though Asiatic like the Loris, it presents more resem- 
blances to the African Potto. The index finger is small; the 
inner of the two incisors is smaller than the outer, but both of 
one side are close together. They may be reduced to one on each 
side of the upper jaw. 
/ VOL. & 2N 
