214 ELEPHAS COLUMBI. 



in the following year (1857) I became cognizant of the most 

 perfectly preserved molar of the same form that I have yet 

 seen. It was discovered in Mexico, and presented to the 

 Museum of the College of Surgeons by Mr. Taylor. This 

 specimen, in conjunction with M. Le Clerc's milk molar, sup- 

 plied the means of determining the ridge-formula of the 

 entire set of molars, and of fixing the exact serial position 

 of the form among the Elephants. 



The whole of these materials I found to be markedly dis- 

 tinct from E. primigenius, and to partake of the characters 

 which are typified in the Georgian molars from the Bruns- 

 wick Canal. But to place the specific distinction from the 

 Mammoth beyond question, I resorted to the crucial test of 

 sawing up the principal molar of the Brunswick Canal series 

 longitudinally and vertically, in the manner figured in the 

 plates devoted to the Elephants, in the ' Fauna Antiqua Si- 

 valensis,' a procedure which commonly quashes at a glance 

 all doubts as to the specific distinctness, or otherwise, of Ele- 

 phant molars, in critical cases. The section yielded colliculi, 

 showing rather thick plates of enamel folded upon cuneiform 

 cores of ivory, of very considerable width at their base, and 

 separated by correspondingly open interspaces filled with 

 thick masses of cement. These characters were strongly in 

 contrast with the attenuated, parallel, and pectiniform dis- 

 position of the materials seen in molar-sections of E. primi- 

 genius ; combined with the dilated outline of the ' discs of 

 wear,' and the decided crimping in the plates of enamel, they 

 led me to regard the form as occupying a place in the series 

 between E. antiquus and E. Indicus, and as differing more 

 from the Mammoth than does the latter from the existing 

 Indian Elephant. These facts were epitomized, but neces- 

 sarily in a very condensed shape, in the ' Synoptical Table of 

 the Species of Mastodon and Elephant,' appended to the 

 memoir which I communicated to the Geological Society on 

 April 8, 1857. l In it, E. (Euelephas) antiquus, and E. (Eue- 

 leph.) Namadicus, respectively Nos. 10 and 11 of the list, are 

 included in the group (/) characterized by ' Colliculi approxi- 

 mate medio leviter dilatati, machceridibus undulatis ; ' while 

 E. (Eueleph.) Columbi (No. 12), and E. Indicus (No. 13), are 

 included in the next group (g), characterized by ' Colliculi 

 approximati machwridibus valde undulatis ; ' and for the ha- 

 bitat of E. Columbi are given Mexico, Georgia, Alabama, 

 with a ' Post-Pliocene (?) age.' Thus, the leading points of 

 the dental characters, and the precise place in the natural 

 series occupied by the species, were distinctly indicated, to- 



1 See p. 14, and Quart. Journ. Geol. Soe., vol.xiii. p. 319. Nov. 1857. — [Ed.] 



