550 FAUNA ANTIQUA SIVALENSIS. 



Plate N, 



Drepanodon {Machairodus) Sivalensis (Falc.and Caut.), or fossil Dre- 

 panodon, from the Sewalik hills. No description of this fossil was ever 

 published, but the Sewalik specimens are referred to by Professor Owen 

 in ' British Fossil Mammalia,' pp. 178,179, and also in ' Odontography,' 

 vol. i. p. 491. A brief description of it is also given by Dr. Falconer 

 in his ' Notes on the Fossil Felis spelcea of the Mendip Hills.' See 

 vol. ii. 



Figs. 1, 1 a, 1 h, and 1 c. — Drepanodon Sivalensis. Fragment of pos- 

 terior portion of skull, showing occipital condyles, foramen magnum, 

 and prominent sagittal crest. — B.M. No. 39,278. 



Fig. 2. — Drepanodon Sivalensis. Mutilated specimen of cranium, 

 including facial portion, but no distinct evidence of teeth. — B.M. No. 

 39,729. 



Figs. 3 and 3 a. — Drepanodon Sivalensis. Fine fragment of upper 

 jaw, right side, Avith apparently the first or deciduous dentition. The 

 crown of the canine is broken off, but what remains is seen to be flat, 

 and very finely serrated along the posterior edge, like a shark's tooth. 

 The tooth evidently bore the same proportion to the molar series as 

 does the canine of the Felis megantereon of Bravard {Vide Owen, 

 Brit. Fos. Mam. p. 178)._B.M. No. 16,350. 



The following note, from Dr. Falconer's Note-book, dated October 2, 

 1858, probably referred to this specimen and to that represented 

 in fig. 5 : — 



' In the Sewalik Machairodus the right upper carnassier is formed with a very- 

 thin bkide. The anterior lobe is damaged, but judging from what remains it 

 would seem to have been two-lobed. The middle lobe is thin and pointed ; but 

 neither the anterior lobe nor the middle one bears the slightest indication of 

 an internal tubercle. If ever there, it is gone. Owen describes it as being there, 

 " but less developed than in the normal species of FtlidcB.''' The posterior lobe is 

 nearly horizontal and very trenchant ; in fact, the tooth is compressed and sharp- 

 edged. All the points rise. The length of the crown is -75 inch. There is an 

 interval between the carnassier and canine of 0-8 in., part of which has been arti- 

 ficially rubbed down, but there is not the least indication of a fang-pit or fang. 

 (Owen says there is, and that it is single-fanged and simple !) There is a distinct 

 show of a double fang, fore and aft, of a tubercular in a line with the sectorial, 

 behind it. The breadth of the canine at its base is 0-5 in. It is very compressed. 

 The posterior concave edge is finely serrated. (Owen says that both edges are 

 distinctly serrated.) ' 



This specimen is also figured in Plate XXV. fig. 5. 



Figs. 4 and 4 a. — Drejmnodon Sivalensis. Fragment of lower jaw with 

 three premolars, the last being the sectorial. Professor Owen refers to 

 this specimen in the following description : — ■ 



' A portion of the lower jaw of a larger Machairodus, from the Sewalik range, 

 shows thebeginningof the characteristic downward extension of the symphysis, and 

 the depression on the outside of the ramus for the lodgment of the long upper 

 canine. The molar series, which consists, as in the typical Felines, of three pre- 

 molars, the last being the sectorial tooth, has a longitudinal extent of two inches ; 

 the second molar slightly overlaps the third, which has an antero-posterior extent 

 of eleven lines. This portion of jaw indicates a species of Machairodus as large 

 as the Jaguar ; it most probably belongs to an adult of the same species as the 

 one indicated by the instructive portion of the upper jaw.' (Fig. 3). (Owen, Brit. 

 Foss. Mam. p. 179). 



This specimen is also figured in PI. XXV. fig. 6.— B.M. No. 16,557. 



