438 DIFFICULTY OF DISCRIMINATING SPECIES. CHAP. xxii. 



species of elephant, E. mirificus, Leidy, and E. imperator, 

 have been obtained from the Pliocene formations of the 

 Niobrara Valley in Nebraska, t one of which, however, may 

 possibly be found hereafter to be the same as E. Columbi, 

 Falc. A remarkable dwarf species also (Eleplias Melitensis) 

 has been discovered, belonging, like the existing E. Afri- 

 canus, to the group Loxodon. This species has been esta 

 blished by Dr. Falconer on remains found by Captain 

 Spratt, E.K, in a cave in Malta.* 



How much the difficulty of discriminating between the 

 fossil representatives of this genus may hereafter augment, 

 when all the species with their respective geographical 

 varieties are known, may be inferred from the following 

 fact : Professor H. Schlegel, in a recently published memoir, 

 endeavours to show that the living elephant of Sumatra 

 agrees with that of Geylon, but is a distinct species from that 

 of Continental India, being distinguishable by the number 

 of its dorsal vertebrae and ribs, the form of its teeth, and 

 other characteristics.! Dr. Falconer, on the other hand, 

 considers these two living species as mere geographical 

 varieties, the characters referred to not being constant, as 

 he has ascertained, on comparing different individuals of 

 E. Indicus in different parts of Bengal (in which the ribs 

 vary from nineteen to twenty), and different varieties of 

 E. Africanus, 



An enquiry into the various species of the genus Rhino 

 ceros, recent and fossil, has led Dr. Falconer to analogous 

 results, as might be inferred from what was said in 

 Chapter X. (p. 173), and as a forthcoming memoir by 

 the same writer will soon more fully demonstrate. 



Among the fossils brought in 1858 by Mr. Hayden from 



* Proceedings of the Geological f Schlegel, Natural Historical Ee- 

 Society, London, 1862-, view, No. 5, p. 72, 1862. 



