16 TKICIIOLOGIA MAMMALIUM : 



Composition. No earthy matter can be detected in these scales, either by incineration 

 or treatment with diluted h\dro-ch!oric acid. 



The hair-like processes, issuing from between and under the scales. Fig. 8 represents 

 one of them. The shaft is oval, diameter ^ T by ^ , color corneous, with irregularly shaped 

 lines and dots. On one side a wart-like protuberance. No button. Disks exhibit a 

 white corneous mass, with a small central crack. 



OF THE SCALES OF 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 wool-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 T f 7 by T |^ 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 f of an 

 inch ; diameter ^| T by ^^ of an inch, gradually narrowing to ^^ at the apex. Cortex 

 corneous, diameter j^-g- 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 f the length of its body; com- 

 pressed, convex on the sides, thickest in the middle, tapering to a point; covered rvith 

 small scales and thinly scattered hairs. 



The Field-Mouse (Agricola Pennsylvania of Ord) has a tail which is cylindrical, scaly, 

 and slightly covered with hair. 



OF SCALES UPON THE TAILS OF MONKEYS. Of the Monkeys of the Old World there 

 are said to be 54 species, and of these only one is found in Europe, 36 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.) 



