PTEKODOX AERICANUS. 
221 
antero-postorior. There were three small iiieisors crowded together so as to form nearly 
a vertical row ; the smallest alveolus is on the actual edge of the alveolus o£ the canine. 
The dimensions (in centimetres) of this s[)ccimen are : — 
Total length of the specimen, so far as preserved 2.‘5-8 
Length of the symphysis 8'G 
Depth of the ramus ojjposite the hinder end of tlie sympliysis . 5-5 
,, „ beneath Hi. 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 : — 
pm . 2 
ji»)i. 3 
j}m. 4 
m. 1 
m. 2 
m. 3 . 
Length. 
Width. 
2-3 
11 
2-6 
13 
2-6 
13 
2'1 
10 
2-8 
14 
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 yu)i.3-4 and m. 2 on the left (text-tig. 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 
forw'ards on the side of the face, terminating just behind the large antorbital foramen 
(no./.), which is situated above p7?i. 3. The snout seems to have been broad and massive, 
and contracts a little in width jTist behind p?n. 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 })air 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 oue-rooted 
tooth. Of pin. 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. Fni. 3 consists mainly of a high laterally compressed cusp ; it is narrower 
anteriorly than })osteriorly, 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. Fm. 4 is much larger ; it consists of a high conical backwardly-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 [losterior. 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 borne on a separate 
root. On the antero-external face a small cusp apparently represents the pai-astyle, and 
posteriorly there is a large trenchant talon, the cutting-edge of which is on its inner side. 
iM. 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 autero-iuternal angles of the first and second molars project 
