478 PROCEEDINGS OF THE ACXdEMY OF [M&Y 



firming the view held by Ciivier'" and Owcn/^ that Hyrox is nearly 

 related to the rhinoceros, as shown by its rhinoceros-like incisor and 

 molar teeth, the incisor teeth being developed as in 

 the extinct Rhinoceros incisiviis, the molar teeth 

 presenting essentially the same pattern in both ani- 

 mals; the position of the oesophagus in regard to the 

 stomach, the relatively simple stomach and complex 

 coecum, the perissodactyle number of ribs 22, the 

 hoofs of the unsymmetrical tetradactyle fore-foot 

 and tridactyle hindfoot as in Aceratherium, an ex- 

 tinct hornless rhinoceros, etc. On the other hand, as 

 I^'ig- -■ first shown by Home,'- the placenta in Hyrax is 



zonular, like that of the elephant and carnivora — a fact somewhat 

 inconsistent with the view that would regard Hyrax as a little 

 rhinoceros. Still, it must be admitted, since it has been shown by 

 the writer'^ that the same kind of mammals (Edentata) may have 

 different form of placenta and different kinds of mammals the 

 same form, that the form of the placenta is of little or no value in 

 the classification of the mammalia. In the absence of fossil re- 

 mains of Hyrax, though the extinct Hyracotherium may be some- 

 what allied, it is impossible to assign Hyrax to any livmg form of 

 mammals. For the present, therefore, it may be regarded as siii 

 generis the representative of an extinct order Hyracoidra, of which 

 Dendrohyrax is also a member. As a matter of record, it may be 

 stated that fragments of a species of tapeworm (Moniezia) were found 

 in the small intestine, and also a number of specimens of Ascaris ferox, 

 as identified by my colleague. Prof. Percy Moore. In regard to the 

 urogenital apparatus, its disposition was found to be essentially the 

 same as described by Pallas, George, etc. In the specimen of 

 Hyrax dissected by the writer, the testicles were found lying in the 

 abdominal cavity below the kidneys, and were longer rather than 

 shorter than the latter, as hitherto described. The ureters opened 

 into the fundus of the bladder, the aperture of the left one being situ- 

 ated a trifle lower than that of the right one. The vasa deferentia, 

 as they pass behind the bladder, become so much convoluted as to 

 resemble a second epididymis, terminating finally in two openings 

 situated in the under part of the veru montanum of the urethra. 

 The lower convoluted portions of the vasa deferentia, just referred to, 



'» Ossemens Fossiles, 1834, Tome 3, p. 251. 



'^ Owen, Anat. of Vertebrates, III, p. 742. 



" Led. on Com-p. Anat., Vol. VI, 1S28, PI. 61-62. 



'2 Proc. of Acad, of Nat. Sci. Phila., 19U1, p. 36G. 



