58—24 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
The simple structure of the true molars of the present s})ecimen is also but one step 
in advance on Tetraconodon, where the columns form completely distinct cones, 
Specific clistinctncss and affimitics. — The foregoing comparisons and measurements 
have sufficiently indicated the specific distinctness of the present form from S. scrofa^ 
S. cristatus, and S. harhatas ; and it cannot be identitied with any other existing 
Asiatic species ; from all of Avhich, putting aside mandibular characters, it is 
distinguished by its superior size, and the relath'ely large development of pm. 3 and 
pm. 4 . In the African S. porcus the hinder premolars are stouter than in S. scrofa 
and existing Asiatic pigs, but pm. 3 is narroAA^er than in the crania under consideration ; 
and the last molar shorter in proportion to the preceding teeth. In the form of 
the cranium tlie fossil has been shown to be nearer to iS*. cristatus and its allies than 
to S. scrofa : the species coming nearest to it in this respect being /S. vittatusi^ in 
which the shortness and height of the cranium are especially Avell marked, the 
palate extending a considerable distance behind m. 3 ^ and that tooth having a rather 
shorter talon than in S. cristatus. In both the recent and fossil crania the form of 
the pre-orbital conca\dty is A^ery similar, and the anterior border of the orbit extends 
as far forwards as the middle of m. 3 . The recent cranium, besides its inferior size, 
is readily distinguished by its less prominent zygomatic arches, smaller occipital height, 
and smaller pm. 3 and pm. 4 y In S. verrucosus and S. celehcnsis the cranium is somewhat 
similar in shape to that of S. vittatus^ but the length is generally proportionately 
greater to the height, and the talons of the last molars are of rather more complex 
structure.® The characters of the inferior premolars of the mandible proAusionally 
referred to the present species are quite distinct from those of any existing species. 
Of the fossil species giA^en on the list on pages 51, 52, the only ones Avhich can 
compare in size Avith tlie present form are 8. choerotherium^ 8. provincialis, 8. antiquus, 8. 
crymantliius., and 8. major. The tAvo latter,^ Avhich Prof. Gaudry thinks are probably 
merely A'^arieties of the same species, are readily distinguished by the form of the 
cranium,® Avhich is of an elongated type someAvhat like that of 8. harhatus^ AAnth the orbit 
entirely behind m. 3 , and Avith a very slight parietal constriction. The iq^per molars of 
the Siwalik species are, as Prof. Gaudry remarks,’^ relatively Avidcr ; Avhile in the 
European species the length of m. 3 is considerably less than the united lengths of the tAvo 
preceding teeth : pm. 3 of the latter is also much narroAver than in the Siwalik species. 
The mandible provisionally referred to the latter is distinguished from the mandibles 
of the European forms by its much larger canine, the presence of pm. 1, and the peculiar 
form of pm. 3 and pm. 4 ; as well as b}^ the length of m. 3 exceeding the united 
lengths of the two preceding teeth, the reverse condition preA^ailing in the European 
mandibles, although less markedly in the specimen figured under the name of 
1 Skull figured by Gray, “Hand-List of Edentate, Thick-skinned, and Ruminant Mammals in the British Museum,” 
pi. XXIV., fig. 3 [Aulochcertts viiialm). 
2 In S. vittatm the length of m, 3 is usually less than that of m, t and nn2. 3 Eolleston, op. cit., pp. 267, 274. 
4 Vide Gaudry, “Animaux Foss, et Geol. de I’Attique,” p. 235, pis. XXXVII. -IX.; and “ Animaux Foss, du Mt. 
Leberon,” p. 42, pi. VIII. 
5 Compare “ F.A.S.,” pi. LXIX., figs. 1, 16, with Prof. Gaudry’s figm-es. 
6 Eolleston, op. cit., pi. XLIII., fig. 7. 7 “ Animaux Foss, et Geol. de I’Attique,” p. 242. 
