68 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 20, 



Genera. Formations. 



Xiphodon Lignites de la Debruge. 



Bichodon Hordwell. 



Microtherium Marnes calcaires lacustres, Puy du Dome. 



Amphitragulus Marnes lacustres en Velay. 



Amphimeryx Lignites de Debruge. 



Dorcatherium Miocene d'Eppelsheim. 



Chalicotherium Miocene d'Eppelsheim. 



Aphelotherium Marnes calcaires de Barthelemy. 



Anthracotherium Marnes miocenes de Moissac. 



Hyopotamus Binstead and Hordwell. 



Anchilophus Calcaire grossier de Batignolles. 



Bothriodon Miocene de Moissac. 



Palceochoerus Calcaire lacustre de Cournon. 



Chceropotamus Paris gypsum, and Binstead. 



Chceromorus Calcaire lacustre, Sansan. 



Poebrotherium Eocene (upper ?), N. America. 



Hippohyus Miocene, Sewalik Hills. 



Hippotherium Miocene d'Eppelsheim. 



Hipparion Marnes fluviatiles de Cucuron. 



Heterohyus Miocene, Sewalik Hills. 



Entelodon Lignites de Soissonnais. 



Hycenodon Eocene superieure du Gard ; Hordwell. 



Pterodon Lignites de Debruge. 



Arctocyon Eocene inferieure a la Vere. 



Galethylax Paris gyps. 



Amphicyon Miocene de Sansan. 



Chcerotherium Miocene du Bourbonnais. 



Rhagatherium Eocene of Mauremont, Switzerland. 



All general rules in organic nature have their exceptions, and 

 differ in that respect from inorganic phsenomena, in regard to some 

 of the general laws of which no exceptions have been as yet dis- 

 covered. 



I shall, on a future occasion, discuss the value of the exception to 

 the inference from the body of facts above cited which has been 

 adduced from the Plagiaulax *, and conclude the present paper with 

 some remarks on the bones of the limbs of Pliolophus. 



Description of some of the Bones of the Extremities. " Humerus. 

 PI. IV. figs. 1 to 4. — The humerus, from the right fore limb, mea- 

 sures 4 inches in length. The convex articular surface of the 

 head of the bone, PL IV. fig. 3, is subtriangular in shape, rather 

 flattened above towards the outer side. The great tuberosity is of 

 equal breadth with, but rises above, the articular head. It is 

 slightly grooved obliquely near its outer part, but is not so widely 

 or deeply notched there, as in the Tapir or Hyrax : it terminates 

 by a single convexity. The small tuberosity is not quite so large 

 relatively as in the Tapir and Hyrax, but it is situated, as in them, 



* Quart. Journ. Geol. Soc. vol. xiii. p. 27G. 



