ANCODON GORRINGEl. 
181 
M. 8424. Palatal roo-ioii of skull with toetli. On tlio right si<hi pm. 4 and m. !-?> are preserved, on 
the loft wo d is wanting. Right side lignred PI. XVII I. tig. d. In the figure pm.?> is 
drawn in outline from another specimen (M. 842.5). 
The fourth premolar consists of an outer crescentic cusp and a large inner rounded 
tubercle ; the cingulum is well developed on the inner side. This tooth resembles the 
fourth j)remolar of the other species of Ancodoyi and differs from that of Braclnjodus in 
the absence of a postcro-internal cusp. The molars increase regidarly in size from 
before backwards. They are quadrate in outline, and as in the other members of the 
family are com])osed of five main cusj)S, three anterior and two posterior. These cusi)s 
are lower and much less distinctly selenodont than in the other species of Ancodon 
(?xcept A. porcinus, Gerv., a species which Lydekker* has shown to be intermediate in 
molar structure between the typical species of Ancodon and Antliracotkerium. The 
outer wall is strongly folded into a W-shaped ectoloph, the parastyle and inesostyle 
being very prominent in all the molars, while in m. d there is a large metastyle also. 
The cingulum is strongly developed and continuous round the anterior and inner sides 
of the teeth. This also seems to be the case in A. porcinus and in Bracliyodus, while in 
the more hypsodont species of Ancodon the cingulum is almost wanting on the inner 
side of the teeth, and in Anthracothet'ium it is absent on the inner side of the inner 
main cusps. The dimensions (in centimetres) of the teeth are : — 
Length. Breadth. 
pm. 4 1'2 1'6 
m. 1 1-G 1-8 
m.2 2-2 2-2 
m. 3 2-5 2-5 
Length of molar series 5'8. 
M. 8425. Right maxilla with pm. 3-4 and m. 1-3. The first and second molars are incomplete on 
the outer side. Pm. 3 consists of a long trenchant outer cusp rising to a sharp point ; 
internally the cingulum is well developed and forms a sort of shelf-like 2 :)rojection on 
the postero-internal face of the tooth, which is therefore triangular in outline. This 
tooth is borne on three roots, one beneath the anterior angle, the others arranged 
transversely beneath the wider posterior portion. This tooth is shown in outline on 
PI. XVIII. fig. 3. (pwn 3). The dimensions (in centimetres) of the teeth are : — 
Length. Breadth. 
pm. 3 1’6 1'4 
p??i.4 1'4 1‘7 
m. 1 
m.2 2-2 app. 
m. 3 2-6 
Length of molar series approximately 6'1 cm. 
M. 8423. Portion of palatal region of skull with pm. 3-4, m. 1-3 on the right side, and m. 3 on left. 
The length of the molar series is 6 cm. 
* “ Note on the Anthracotheriidae of the Isle of Wight,” Qeol. Mag. [3] vol. i. (1884) pp. 547-8. 
