RHINOCEROS LEPTORIIINUS. 3G9 



4. The great length of the diasteme ; the distance from the middle 

 of the incisive border to the anterior edge of the antepenultimate pre- 

 molar being exactly equal. 



5. The absence of reclination in the anterior border of the coronoid. 

 It makes an open curve below with the ramus, but the superior part is 

 nearly vertical. 



6. The posterior angle projects behind the neck of the condyle, and 

 is puckered. (The figs, in 5 and 6 of De Christol's thesis very good ; 

 his R. tichorhinus.) 



7. Very long diasteme with sharp raised edges and great constriction 

 of the gutter between them, and then a spathulate expansion in front 

 towards the incisive border ; the anterior portion is curved, and throws 

 out a step, but the form is very different from R. he?nitcechus, and there 

 is nothing of the scaphoid character in the general contour below. 



Dimensions. 



R. megar. Col. Wood's 



No. 2 R. hemiteechus 



Length of 6 last teeth 10o 10- 



Length of 3 (last) true molars ... 6" 6-25 



Length of 3 premolars ..... 4"5 3'8 

 Length of diasteme to incisive border . . 4 - 4 



In both of Gervais' specimens the teeth are adult : i.e. the last are 

 partly worn and the antepenultimate true molar is ground down to a 

 disc. In jaw No. 2, the larger, there are only six teeth (less perfect in 

 the other). In No. 2 there is also a very distinct outer included incisor 

 on the right side, with the alveoli of two middle ones nearly filled up. 1 



II. — Measurements of Skull of Khinoceros Leptorhinus in the 



Museum at Lyons. 



[On his way to Italy, in 1858, Dr. Falconer was presented by Prof. 

 Jourdan with the cast and an unpublished lithographic engraving of a 

 skull of Rhinoceros in the Nat. History Museum at Lyons, with the fol- 

 lowing inscription : ' Tete de Rhinoceros megarhinus des sables d'eau 

 douce trouvee par M. Jourdan le 12me Fevr. 1856, a Lens Letang, pres 

 Moras, Drome.' This cast was subsequently compared with the Rhino- 

 ceros remains in the various museums of Italy, in the descriptions of 

 which it is frequently referred to. There is no description of the skull 

 in Dr. Falconers Note-books, but the skull and molar series have been 

 reproduced by Mr. Dinkel in PL XXXI. figs. 2 and 3, and I am indebted 

 to Mr. W. H. Flower, F.R.S., for his assistance in taking the following 

 measurements of the cast, which is now deposited in the British 

 Museum. — Ed.] 



1. Extreme length of skull from summit of occipital crest to point, of pre- 

 mnxillary bones, 25'5 in. 2. Extreme length of ditto from posterior plane of 

 occipital condyles to broken edge of left diasteme, 233 in. 3. Extreme length of 

 ditto to anterior edge of alveolus of 2nd premolar, 22'4 in. 4. Length from 

 auterior border of right orbit to outer edge of occipital plane, left side, 15'2 in. 



1 Dr. Falconer's Note-book also con- 

 tains a description of a mutilated skull 

 of R. megarhinus (sic) in the Bishop's 

 Palace at Montpellier, examined by him 

 on Nov. 21st, 1858. Nearly the whole of 

 the nasal sinus was filled with pebbles 

 VOL. II. B B 



and gravel, so that it was impossible to 

 be certain whether or not there was a 

 septum, but Dr. F. was inclined to agree 

 with De Christol and Gervais in think- 

 ing there was none. — [Ed.] 



