70 H. LydeTiher — On Fossil Mammalia. 



separated by a long diastema from fhe rest. The six approximated 

 teeth are the last three premolars, and the three molars ; the latter 

 being in a partially worn condition, which indicates the fully adult 

 condition of the specimen. The dentition is essentially brachydont, 

 and it will suffice to say that the last six teeth agree precisely in 

 form with those of typical species of Anthracotherium, and are in 

 fact miniatures of those of some of the larger species of that genus.* 

 The true molars differ in toto from those of typical species of Hyopo- 

 tamiis, like H. bovimis ; although they approach those of some of the 

 aberrant species like J3". porcinus.^ The second premolar ( pm. 2 ) has 

 a compressed simple crown ; pm- 3 has a triangular crown ; and 

 P"^- 4 has a distinct inner and outer column. These teeth are pre- 

 cisely like those of Aniliracotlierium, and differ slightly from those of 

 the typical forms of Hyopotamus.^ The isolated tooth ( pm. 1 ) has 

 a compressed conical crown, and is inserted by two distinct fangs, 

 whence it may be regarded as the first premolar ; from its relation 

 to the nasals it was probably situated but a short distance behind the 

 canine. In the larger species of Anfhracotherium, the first premolar 

 is either in contact with pm^ 2,* or is separated by a comparatively 

 small interval,^ but the complete dental series of some of the smaller 

 forms like A. hreviceps^ is not known. In the typical species of 

 Hyopotamus ' there is a long diastema between pni' 1 and pm- ^ , 

 but there is a still longer one between the former and the canine. In 

 Choeropotamus parisiensis^ there is a long diastema between P"^- 1 

 and pm- 2 ; although this is proportionately smaller than in the 

 pi'esent specimen, and the first premolar is relatively larger. The 

 true molars of Choeropotamus are, however, readily distinguished by 

 their more bunodont structure from the decidedly selenodont teeth 

 of the present form. The crushed condition of the cranium admits 

 of but little accurate observation. As in the Anihracotheriidce in 

 general, there is no tympanic bulla; the orbits are well defined, 

 although incomplete posteriorly ; there is a strong sagittal crest ; and 

 the nasals are relatively long. The occiput is like that of Anihrd- 

 cotherium and Eyopotamus. The anterior border of the posterior 

 nares is situated a considerable distance behind m- 3 ; which is a 

 character found in Anthracotherium dalmatinum,^ and not in any of 

 the typical species of Myopotamns}^ 



The lower jaw shows both rami of the mandible, which have 

 however been disassociated. The right ramus and the dentition are 



^ Compare Anthracotherium illyricum, Teller, Beitr. Pal. Oest. Ungar. vol. iv. 

 pt. i. pi. xi. 



2 Vide supra, vol. i. p. 547 (1884). 



3 Vide Filliol, Ann. Sci. Geol., vol. xii. pis. xv-xix. 

 * A. illyricum, Teller, op. cit. 



5 A. ahaticum. Vide Filliol, Ann. Sci. Geol. vol. viii. pi. viii. (1877). 



^ Vide Bottger " Pala3ontograpliica," vol. xxiv. pt. 5, pp. 163-173. 



■^ Vide Filhol, Ann. Sci. Geol. vol. xii. pis. xv-xix. 



^ Gervais, Zool. et Pal. Fran^aises, 2nd ed. pi. xxxii. fig. 1. 



^ Teller, op. cit pi. xiv. Prof. Teller refers this species to a separate genus — 

 Trominatherium; but the present writer prefers to continue to refer Mio Anthra- 

 cotherium. 



10 Filhol, he. cit. 



