172 TEETIAET VEETEBEATA OE THE EATtM. 



Incert^ sedis. 



Family BARYTHEEIID^. 



This family is known only from a single genus, Barytherium, the characters of 

 ■which are given below. Its systematic position is still very doubtful and it does not 

 fall within the limits of any of the suborders as at present defined. In a former 

 paper * it was suggested that possibly it may be found to constitute a subdivision 

 of the Amblypoda, which would be of the same rank as the Dinocerata and might be 

 called the Barytheria. 



Genus BARYTHERIUM, Andrews. 

 [' Nature/ Oct. 10th, 1901, vol. kiv. p. 577; also Geol. Mag. [4] vol. viii. (1901) p. 528.] 



1901. Bradyiherium, C.W.Andrews, Tageblatt des V. Internationalen Zoologen-Congresses Berlin, 



No. 6, p. 4 ; also Geol. Mag. [4] vol. viii. pp. 407-8, figs. 3-4 (September) ; also the 

 ' Zoologist,' p. 319. [Name preoccupied in March 1901 by G. Grandidier for a genus 

 of extinct Edentates from Madagascar (Bull. Mus. d^Hist. Nat. Paris, vol. vii. p. 55.] 



1902. Barytherium, C. W. Andrews, Verhandlungen des V. Internationalen Zoologen-Congresses 



Berlin, p. 528. 



The dental formula, so far as known, is : ^. nj^), c. q, pm. 3, m. g. The first lower 

 incisor is a large procumbent tusk in contact with its fellow in the middle line, and 

 separated from the anterior premolar by a long diastema ; the molars of both jaws are 

 bilophodont, the last lower molar having a talon. The mandible is extraordinarily 

 massive, the symphysis being very long and deep ; on its ventral border there is a pair 

 of blunt tuberosities. The anterior border of the ascending ramus rises on the side of 

 the jaw beneath m. 2. The humerus is very massive, with greatly expanded distal end, 

 in which all the muscle-ridges are strongly developed. 



Skull (PI. XVII. fig. 4). — The only portions of the skull at present known are parts 

 of the right and left maxillee bearing the cheek-teeth. On the left side the zygomatic 

 process {zyg.) is preserved: it is of great width, its base extending from above the 

 anterior lobe of m. 1 to the middle of pm. 2, a distance of about 13 cm. ; its ventral 

 edge is nearly parallel to the alveolar border and very little above it ; its upper surface 

 is completely cut away by sand-drift, and, the anterior edge being somewhat imperfect, 

 it may have been considerably wider even than is shown in the figure. 



Upper Dentition (PI. XVII. fig. 4). — Of the upper teeth pm. 2-4 and m. 1-3 are 

 present on the left side ; the premolars, especially jo??i. 2, are imperfect on their inner 

 side and the crowns of all the teeth are greatly worn. Pm. 2 seems to have been more 



* "Note on the Barypoda, a new Order of Ungulate Mammals," Geol. Mag. [5] vol. i. 1904, p. 482. 



