INTRODUCTION. G3 



formity, which even then point to a further sub- 



Equidae seem appropriately placed between 

 Pachydermata and Ruminants, from their conforma- 

 tion being intermediate,* and also, because they are 

 found in a fossil state, accompanying the debris of 

 both, and thereby proving that they co-existed in a 

 former Zoology, or at least in a Zoological distribu- 

 tion, more ancient than the present ; for, among the 

 organic remains in limestone caverns, in osseous 

 breccias, in tertiary or alluvial strata, (the pliocene of 

 Lyell) in the fresh water deposits, and in the Eppes- 

 heim sand, among several species of Elephant, of 

 Rhinoceros, of Bovine and Cervine genera, their 

 bones are found along with the remains of a former 

 hyaena, or of a species perhaps still extant. Their 

 debris, often in great abundance, are spread over 

 an immense surface of the Old World, from eastern 

 Tahtary to the west of Ireland, and from the Polar 

 regions to the south of the Himalaya mountains,^*] 

 and to an unknown distance in northern Africa,t I 



* Such a9 the rudiments of two other toes attached to each 

 of the canon bones, the structure of the stomach, the teeth, are 

 pachydermous ; the consolidation of the phalanges, separately 

 immoveable, homogenous ; but the conformation of other parts 

 approximates the ruminantial character. 



f We have seen teeth of Equidae found in Polar ice, along 

 with the bones of the Siberian Mammoth, others from the 

 Himalaya range, down to its southern spurs, mixed with frag- 

 ments of lost and unascertained genera ; many more from the 

 Oreston and Torquay caverns, with bones and teeth of hyaena 

 and sheep; some from Ireland, and one from Barbary, com- 



