118 Mammalia. Peculiar Glands. 



back*-. In many Ruminants and Hogs an inverted fold of skin just 

 below the orbit ('suborbital sinus') receives the secretion of numerous 

 sebaceous follicles by which it is perforated. Glandular depressions 

 of the skin situated in the groin ('inguinal pits') are found in many 

 Antelopes, and are especially noticeable in the small Ruminant 

 called on account of the odour of the secretion * Musk Deer.' 



In-Fnamellata. The short vestibule or cloacal passage of the two- 

 toed Sloth shows orifices of many sebaceous follicles. 



In all Marsupialia there arc two cavities with sebaceous follicles 

 opening into or near to the termination of the rectum. 



Monotremata. In the male Ornithorhyncus and Echidna there is a 

 considerable triangular gland on the outer side of the leg, between 

 the femur and the long olet^ranoid process from the head of the 

 fibula ; the duct from this descends down the back of the leg to the 

 tarsus, where it suddenly expands into a vescicle applied to the base 

 of the spur (cf. Osteology) and is thence continued as a minute duct 

 into the canal which traverses the spur, and which terminates by a 

 fine longitudinal slit about one line distant from the point. 



* The resemblance of this orifice to the navel on the opposite part of the trunk 

 ftiiggestcd to Linnajua the term Dicotyles for this genus of S. American porcine 

 animals. 



