QUATEENAET FAUNA OF GIBEALTAE. 61 



the open alveoli of the first and second premolars (pm. 1 and pm. 2), the latter much 

 smaller than the former; the fourth premolar (pm. 4) recently broken off, but the 

 fangs remaining in the alveolus ; the first molar perfect and unworn, and about two 

 thirds of the second molar. The vertical diameter of the ramus at the second molar 

 tooth is about l"-4, and the same at the diasteme. The diasteme measm-es l"-0, and 



the symphysis 2"-0. The teeth measure : — 



in. 



^STT •25X-25 



^^~2 -lOx-lO 



5^71 •40X-21 



^71 1-0 X -5 



^^ 1-1 X -64 



The teeth in other respects correspond exactly in pattern with those in the other 

 mandible above described, the only difference at all worthy of note being that the first 

 molar is slightly narrower. 



4. The next specimen is the anterior part, also of a right mandible (PI. IV. figs. 3, 4), 

 of a fully mature animal, containing the canine with the apex recently broken off, the 

 open alveolus of the first premolar (pm. 1) close to the canine, the fourth premolar 

 (pm. 4) fortunately quite entire though somewhat worn, with a portion of the 

 alveolus of the first molar (m. 1) filled with stalagmite. There are no traces of the 

 alveoli of the second and third premolars. The fracture by which this portion was 

 detached from the remainder of the jaw is ancient, the surface being covered with hard 

 stalagmite ; and it may not very improbably have been the work of the Hysena. 



The diasteme measures l"-7; and the vertical height of the ramus at that part is l"-7 ; 



the length of the symphysis 2"-5. The teeth measure : — 



in. 



Canine -Qx-T 



"^^n. •20X-20 



pm. 4 •47X-25 



This specimen is particularly valuable in a diagnostic point of view, from its presenting 

 the fourth premolar in a tolerably perfect condition. The dimensions of this tooth 

 show its small size as compared with the other teeth ; and in its pattern it also 

 corresponds exactly with the usual form of the same tooth in U. arctos, as will after- 

 wards be more particularly pointed out. 



5. The posterior half, or nearly so, of the left mandible of a young animal, but 

 apparently not the same individual as that to which the immature mandible above 

 described belonged, since the teeth appear to be rather larger. The specimen has been 

 much comminuted; and different portions were found widely apart; so that at the 

 time when the figures were prepared the several fragments had not been recognized 

 as belonging to the same bone, and consequently one portion only of it is represented 

 VOL. X. — PAKT II. No. 2. — August \st, 1877. s 



