ELEPHANT AND MASTODON. 117 



in section, with a deep keel below and broad above, where it shows two 

 pairs of costal articular surfaces, and the commencement of a third 

 pair, the bone being there broken off. The uppermost pair of discs 

 appear to represent the jimctiou with the first pair of ribs? The 

 specimen was enveloped in a mass of calcareous sandstone, which left a 

 small portion exposed. The episternal portion is wanting. 



Dimensions. 



Inches 



Length of the fragment 12-7 



Depth at anterior end ......... 6'3 



Ditto in the middle ......... 6'5 



Width of upper surface, anterior end 4-9 



The upper (vertebral surface) forms two hollows bounded by ridges, 

 i.e. two sternal elements. 



No. 1. Elephas insignis. — Lower jaw, left side, comprising the anterior 

 portion of the horizontal ramus, truncated in front of the symyhysis, 

 containing six ridges of a molar tooth, the three anterior of which are 

 worn, the rest intact ; broken off behind near the commencement of 

 the ascending ramus ; covered over with soft sandy matrix. Vide 

 JoTirn. As. Soc. vol. xix. p. 489. This specimen is in the usual mineral 

 condition of the Nerbudda fossils as contrasted with those from Ava and 

 the Sewalik hiUs, viz. being white, soft and friable, and adhering to the 

 tongue, there being no ferruginous or calcareous infiltration. It is of 

 great importance, as being the only specimen of this Sewalik Stegodon 

 from the Nerbudda in the Asiatic Society's collection. 



II. — Descriptions by Dr. Falconer of Fossil Eemains of Mastodon 

 IN Museum of Asiatic Society of Bengal. 



A. From the Sewalik Hills. 



No. 1. Mastodon Sivalensis. — Fine specimen of the upper maxilla 

 left side, comprising the greater portion of the palate and two molars 

 embedded in the jaw, with four empty pits, marking the situation of 

 the fangs of the second milk molar which had fiillen out. The third 

 milk molar is shown nearly entire, with the enamel crown broken off 

 at the outside of the first two ridges, and the first three ridges are seen 

 to be touched with wear forming depressed cups. The crown of the 

 tooth is bisected longitudinally into an outer and inner division, and 

 the groups of mammillae are seen to alternate, instead of being trans- 

 verse with accessory mammilla in the valleys (See PI. IX. fig. 2). 

 This is the normal character of the species distinguishing it alike 

 from M. latidens and M. Perimensis (PI. IX. figs. 3, 4, 5, and 6). 

 The sru-face of the enamel is deeply grooved vertically, so that 

 the ridges, when worn dowTi, present a very complex pattern. Behind 

 the fourth ridge is a talon consisting of a complicated group of 

 small mammiUse. To the rear of this tooth, the anterior portion of the 

 first true molar is visible in germ, and the posterior part of it is stiR 

 concealed in the alveolus ; it shows three ridges, presenting the same 

 complex form as the anterior tooth, but is very considerably larger in 

 every proportion. The four empty fang cavities in firont are nearly 

 square, sho-^ving that the crown of the tooth had a similar form, viz. that 

 _ it was short and broad ; these cavities are well apart from each other. 



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