FROM THE CAPE OF GOOD HOPE. 199 
EXPLANATION OF PLATE XI. 
Titanosuchus ferox. 
Fig. 1. Inner side view of a portion of the left maxillary. 
. Horizontal or transverse section of the alveolar border and implanted 
roots of the molar teeth of the same maxillary. 
. Transverse section of the root of the first upper incisor. 
. Longitudinal section of the root of the same tooth. 
. Longitudinal section of the root of the eleventh molar of the left 
maxillary. 
Symphysial end of left mandibular ramus, with the alveolar border in 
horizontal section. 
. Horizontal section of the alveolar border and roots of the molars of 
the same mandibular ramus. 
. Vertical or longitudinal section of the implanted root of the canine of 
the same ramus, 
. Longitudinal section of the root of the third molar of the same 
ramus. 
(All the figures are of the natural size.) 
mo OM WD hE DOE 
Discusston. 
The Presmpent congratulated the Society on receiving such a 
number of valuable papers from Prof. Owen. 
Prof. Szerey spoke of the great clearness of description by which, 
even in the absence of the specimens, Prof. Owen had been able to 
bring the matter before the Society. He remarked, however, on the 
difficulty of arriving at reliable conclusions from specimens in which 
not a single crown of a tooth was preserved. He pointed out that 
the fang of the teeth of Ichthyosawrus, Plesiosawrus, and other forms 
of extinct Reptilia was often found to be closed, and with no trace 
of a successional tooth. He thought that this absence of a succes- 
sional tooth was not sufficient to warrant the establishment of a new 
order of reptiles to receive this species, and that the characters of 
the specimen were so far Crocodilian that, if it had been found in 
England, it would have been included in the Crocodilia. 
Mr. Hvxxz supported Prof. Seeley in his objections, and in con- 
firmation of these stated that in Zguanodon and Hypsilophodon the 
tooth-fang was often found closed, and without any trace of a suc- 
cessional tooth. The same was true occasionally of Goniopholis. 
Prof. Owzn always felt pleasure in submitting the results of his 
studies to the Geological Society, because that was to submit them 
to the competent criticism of his fellow workers in the same field. 
He expressed doubt (until actual specimens were shown him) that 
any Goniopholis teeth had been found without traces of successional 
teeth below them. He defended his foundation of the group of 
Theriodonts from the mode of the implantation of the teeth in their 
jaws. He stated that the materials on which this paper was 
founded are a portion of the valuable series of specimens (900 in 
number) obtained by Mr. T. Bain, the son of the well-known 
explorer, who had received a grant of £200 from the Treasury to 
aid him in searching for and transporting these South-African fossils. 
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