DESCRIPTION OF PLATES. 523 



Plate LXXX. 



Chalicotherium Sivalense (Falc. and Caut.). See antea, page 208, and 



PL XVII. 



Figs. 1, 1 a,.lb, and 1 c. — Anterior half of an adult head, Avith the 

 upper and lower jaws in natural apposition, and exhibiting the greatest 

 portion of the dental series of both jaws. The greater part of the 

 cranium proper is absent. The specimen demonstrates the very re- 

 markable fact that the Chalicotherium Sivalense was entirely destitute 

 of incisor teeth in either jaw. The intermaxillary bones are perfect to 

 their tips, and consist of slender slips of bone converging to a sharp 

 point ; they show that no incisor teeth could have existed in the upper 

 jaw at any period of the animal's age. The anterior portion of the 

 lower jaw is perfect to the alveolar edge. A detached canine is seen 

 on either side, but the intervening space is without a vestige of incisors, 

 and is contracted in correspondence with the convergence of the 

 intermaxillary bones, and sloped off to a fine edge. The upper jaw 

 is also destitute of canines, or of any ti'ace of canine alveoli ; but 

 the lower jaw contains two canines, as shown in figs. 1 a and 1 b, 

 the crowns of which are thick, cuneiform, and somewhat triangular, 

 and slightly inclined forwards, with a blunt apex. The specimen 

 shows three premolars and the first true molar ; the two back molars 

 are absent. The characters of the molars are better seen in figs. 3 

 and 4, and are described in great detail in the memoir on Chalico- 

 therium (Page 213). 



This beautiful specimen was originally in the Dadoopoor collection 

 of Messrs. Baker and Durand, and is now in the Museum of Marischal 

 College, Aberdeen. Cast in B.M. Its dimensions are as follows : — 



Length of intermaxillary bone of right side, 3' in. Greatest depth of ditto, 

 •4 in. Length of three premolars and first molar, 2-6 in. Length of three premo- 

 lars, I'Sin. Breadth of fragment opposite last premolar, 3-2 in. Breadth of pa- 

 late '5 in. in front of anterior premolar, 1'6 in. Breadth of palate V2 in. in front of 

 anterior premolar, l"lin. Height of fragment of maxillary bone from alveolar 

 border (right side), 2'5 in. Length of fragment of maxillary bone on right side, 

 3'9 in. Greatest breadth of anterior nares, 1'3 in. Extreme length of fragment 

 of lower jaw, 5-5 in. Length of symphysis, 3-1 in. Depth of horizontal ramus at 

 posterior border of first molar, 1-6 in. Greatest thickness of ramus at ditto, -8 in. 

 Interval between the horizontal ramus at ditto, 1 ■ in. Breadth of lower jaw at 

 posterior border of symphysis, 2-2 iu. Least breadth of symphysis, I'lin. From 

 posterior border of sjrmphysis to narrowest part of symphysis, l'9in. Between 

 alveolar border of canines, l'2in. Breadth of incisive margin, -9 in. Width of 

 palate posteriorly between first molars, 1-3 in. Length of first premolar, upper 

 jaw, right side, -5 in. Length of second premolar ditto, -So in. Length of third 

 premolar (greatest) ditto, -7 in. Length of first molar ditto, -95 in. Breadth 

 of first molar ditto, 1-03 in. Breadth of third premolar ditto, -9 in. Breadth of 

 second premolar ditto, '76 in. Breadth of first premolar ditto, '53 in. Length of 

 three premolars and first molar, 2'8 in. Length of three premolars, I'S in. Be- 

 tween opposed margins of canine and first premolar, -Qm. Between anterior 

 margin of first premolar and incisive margin, 17 in. Length of first premolar, 

 lower jaw, '6 in. Length of second premolar, ditto, "Gin. Length of third premo- 

 lar, ditto, -S in. Length of first molar, ditto, TO in. Breadth of first molar, ditto, 

 •6 in. Breadth of third premolar, ditto, '5 in. Breadth of second premolar, ditto, 

 •43 in. Breadth of first premolar, ditto, '3 in. Length of crown of canine, -46 in. 

 Breadth of crown of canine, '3 in. 



' Fig. 2. — Chalicotheriiim Sivalense. Upper jaw, right side, with part 

 of orbit, three true molars and last premolar. The muzzle seems 

 to have fined off rather abruptly in front of the molar protuberances, 



