16 TRICHOLOGIA MAMMALIUM; 
Composition —No earthy matter can be detected in these scales, either by incineration 
or treatment with diluted.hydro-chloric acid. 
The hair-like processes, issuing from between and under the scales. Fig. 8 represents 
one of them. The shaft is oval, diameter 545 by 45, color corneous, with irregularly shaped 
lines and dots. On one side a wart-like protuberance. No button. Disks exhibit a 
white cormneous mass, with a small central crack. 
OF THE ScaLes or PREHENSILE TAILS OF SOME OF THE LOWER ANIMALS, AND THE Hairs 
ACCOMPANYING THE SAME.—Scales are found upon the tails of some of the lower animals. 
They may, possibly, be considered as hairs only partially developed; the matter which 
forms the ordinary scales of the cortex being in abundance, while that which forms the 
fibres is deficient. Their study may therefore prove interesting, both in themselves and 
on account of their connection with hair-scales and mool-scales, which are the subject of a 
separate part of this work. 
The Scales upon the Tail of the Possum.—(See fig. 9.)—These scales are, in general, 
oval and sub-oval, depressed upon the side of the attachment to the epidermis; diameter 
about 35 by ;75 of an inch. ‘They are the same color as the epidermis, which they cover. 
Hairs never issue out of these scales, but always from between them. They also partake 
of the color of the skin, whether that be black or white. They are in length about # of an 
inch; diameter z1, by 34, of an inch, gradually narrowing to ;}; at the apex. Cortex 
corneous, diameter ;;!,5 of an inch; the remainder of the interior oval and white. When 
the scales are removed, the inferior termination of the hairs, which they overlay, may be 
seen in the dermis. 
The Muskrat (Fiber Zibethicus of Lin.) has a tail 3 the length of its body; com- 
pressed, convex on the sides, thickest in the middle, tapering to a point; covered with 
small scales and thinly scattered hairs. 
The Field-Mouse (Agricola Pennsylvanica of Ord) has a tail which is cylindrical, scaly, 
« 
FRol 
and slightly covered with hair. 
Or ScaLes upon THE TAILS or Monkeys.—Of the Monkeys of the Old World there 
are said to be 54 species, and of these only one is found in Europe, 86 in Asia, 16 in 
Africa, and 2 whose country is unknown. 
One of the distinguishing features of the Monkey of South America, is the having of a 
tail; but we observe that a species of Lemur is found in Madagascar, possessing a very 
long tail, peculiarly adapted to climbing. 
Of the South American Monkeys, that have tails, all are not prehensile. Those with 
these strong, muscular, scaly tails, are called “Sapajous,” and those with feeble, useless 
tails, are called “Sagoins.” Of both these there are several varieties. Of the first,’the 
Coati (Atelesater) has no thumb, and consequently but four fingers on the two fore-paws, 
but the defect is supplied by the tail, with which this animal slings himself from tree 
to tree. 
Of the Sagoins, or Monkeys which do not hold by the tails, is the Samari, or Aurora. 
(Sanguinas sciureas.) 
