222 ELEPHAS COLUMBI. 



enamel are thicker than in the Mammoth, and abont equal 

 to those of the Indian Elephant ; they present a considerable 

 amount of parallel shallow plaiting, which is prominently 

 shown where they rise above the level of the cement. The 

 wear of the crown takes place in a succession of steps, from 

 the front backwards, which it is of importance to notice with 

 reference to the inferred food of the species. These steps 

 rise like a flight of stairs, each being composed of the whole 

 mass of cement of one of the valleys and the combined 

 enamel-plates and ivory of the ridge immediately behind it. 

 There are five of these steps in the Georgian specimen, the 

 posterior ridges being intact. 



The dimensions are as follow : — 



Length of crown, measured at the base, 9.5 in. Ditto ditto at summit of crown, 

 6'9 in. Width of crown in front, 3'2 in. Ditto at fourth remaining ridge, 3'5 in. 

 Ditto behind, at widest part, 3'3 in. Height of ditto, at eighth plate where un- 

 worn, 6'2 in. Ditto of anterior worn plate, 2'5 in. 



PI. X. fig. 1, represents a longitudinal section of the spe- 

 cimen, by which the specific distinction from the Mammoth 

 is best shown. The plates converge from the convex base to 

 the summit irregularly, but somewhat like the voussoirs of 

 an arch ; so that the same number of plates diminishes from 

 9 '5 inches at the base to about 7 at the crown. The ridges 

 are not so high as in the Mammoth, and their constituent 

 elements, i.e. the enamel, ivory, and cement, are thicker. In 

 the interval between the 10th and 11th ridges the cement 

 attains, near the base, the excessive thickness of six -tenths 

 of an inch, being about twice as much as what is ordinarily 

 seen in the section of the Mammoth. For the contrasted 

 difference I refer to the sections, PI. I. fig. 1, of the ' Fauna 

 Antiqua Sivalensis.' (See vol. i. PI. V. fig. 3.) 



The specimen next to be noticed is No. 33,218 of the MSS. 

 register, British Museum, Palseont. Gallery. It was acquired 

 of Mr. Bollaert, and it bears a record of having been procured 

 from San Felipe de Austin, on the Brazos River, in Texas. 

 It is figured in the ' Geologist.' ' This superb morceau 

 consists of the posterior three-fourths of the last true molar, 

 lower jaw, left side, well advanced in wear. The crown 

 presents the remains of the posterior fourteen ridges and 

 hind talon ; the anterior portion had been ground down by 

 use, and has disappeared. The two anterior ridges are worn 

 to the base, and confluent in a common depression of ivory, 

 upon which a slight islet of enamel remains. Of the suc- 

 ceeding ridges, the next seven are worn down into transverse 

 discs, which are open, and bounded by highly crimped and 

 thick plates of enamel, bearing a close resemblance in this 



1 Vol. v. p. 57, PL ir. 



