PTEEODON ATEICANUS. 221 



antero-posterior. There were three small incisors crowded together so as to form nearly 

 a vertical row ; the smallest alveolus is on the actual edge of the alveolus of the canine. 

 The dimensions (in centimetres) of this specimen are : — 



Total length of the specimen, so far as preserved 23'8 



Length of the symphysis 8'6 



Depth of the ramus opposite the hinder end of the symphysis . 5-5 



,, „ beneath m. 2 5'8 



,, » „ m. 3 5-7 



Transverse diameter of the canine alveolus 2 app. 



Antero-posterior diameter of the canine alveolus 2*7 app. 



The dimensions (in centimetres) of the teeth are : — 



Length. Width. 



pm.2 2-3 11 



pm. 3 2"6 13 



jsm. 4 2'6 13 



m. 1 2-1 10 



TO. 2 2-8 14 



TO. 3 3-4 17 



C. 10192. Anterior part of a much-crushed skull in which pm. 2-4 and m. 1 are preserved on the 

 right side and jom. 3-4 and m. 2 on the left (text-fig. 69). On the left side the upper 

 portion of the muzzle is preserved about as far back as the anterior border of the orbit, 

 from beneath which a strong ridge, probably continued from the zygomatic process, runs 

 forwards on the side of the face, terminating just behind the large antorbital foramen 

 [ao.f.), which is situated above pm. 3. The snout seems to have been broad and massive, 

 and contracts a little in width just behind pm. 2, but the whole is greatly fractured, so 

 that it is not possible to be sure of its original form. The anterior part of the palate is 

 concave from side to side and there is a pair of large anterior palatine (incisive) foramina 

 (a.p.f.), elongate-oval in form and apparently situated between the canine alveoli. All 

 the incisors and the canine are wanting, and their alveoli so crushed and imperfect that 

 nothing can be said about them. Fm. 1 seems to have been a small, perhaps one-rooted 

 tooth. Of pm. 2 the hinder half is preserved on the right side ; it had a high laterally 

 compressed conical crown, probably somewhat curved backwards, and there were two 

 roots. Pm. 3 consists miiinly of a high laterally compressed cusp ; it is narrower 

 anteriorly than posteriorly, there being a slight prominence at the postero-internal angle. 

 There is a small tubercle on the hinder slope of the main cusp near its base, and this tooth 

 has two roots. Pm. 4 is much larger : it consists of a high conical backvrardly-sloping 

 cusp, connected with the hinder edge of which is a short cutting-talon ; on its inner 

 anterior side there is a small keel-like prominence borne on a separate root ; there are 

 three roots in all, two anterior and one posterior. M. 1 is a large triangular tooth ; it 

 consists of a large pointed main cusp, obscurely divided into two by a shallow vertical 

 groove, and connected antero-internally with a small but distinct cusp Lome on a separate 

 root. On the antero-external face a small cusp apparently represents the parastyle, and 

 posteriorly there is a large trenchant talon, the cutting-edge of which is on its inner side. 

 M. 2 is similar to m. 1 in structure, but larger. M. 3 cannot be made out, but it must 

 have been a small tooth. The antero-internal angles of the first and second molars project 



