340 SYKOPSIS OF THE VEUTEBKATE FAUKA OF THE PUERCO SERIES. 



Chriacus ruetimeteranus sp. nov. 



This is the largest species i-efeired to the genus, and is the only one as yet I'epre- 

 sented by a single individual. I possess part of the left mandibular ramus which 

 exhibits the true molars, and the roots of the first and second premolars. 



The last molar is as large as the second, and its anterior cusps are not opposite 

 to each other as in other species of Chriacus, but the external is in advance of the 

 internal. The fifth cusp is not elevated as in other species, but is represented by an 

 internal angle of an interior ledge, which is quite wide. The anterior cusps of the 

 m. i are opposite, those of m. ii are injured. The heel has the external cusj) of cres- 

 centic section, and the internal elevated border. ISTo cingula. Enamel obsoletely 

 coarsely rugose. The heel of the m. iii is well developed, as are also the adjacent 

 internal and external marginal cusps. 



Measurements. M. 



f anteroposterior 009 



Diameters m. i \ .„„ 



(^ transverse OUo 



f anteroposterior 010 



Diameters m. iii - ..._ 



I transverse UOoo 



Depth of ramus at posterior end of m. i OKi 



" m. iii 031 



From the lowest Puerco beds. Dedicated to Prof. L. Euetimeyer, the distin- 

 guished palaeontologist of Basle. 



CniiiACUS BALDwiNi Cope. Deltatherium haldwini Cope; Proc. Amer. Phil. See, 1883, p. 463; Tertiary Vertebrata, 

 1885, p. 283, PI. XXIII d, fig. 13. 



Besides the type of this species, I have obtained since its description, the greater 

 |)art of the mandibulai' ramus with teeth with several parts of the skeleton, of one 

 individual, and both mandibular rami with most of the teeth of a third individual. 

 Parts of the rami of a fourth individual may belong to the species. 



The complete rami show that their anterior portions are produced, and that the 

 premolar teeth in front of the second are spaced. The second and third are close 

 together. The true molars themselves are a good deal like those of the M. snhtri- 

 gonus with fifth cus}). llie internal cusp of the first premolar is rudimental in this 

 species. 'I''he premolars of the M. suUvigoii.us are not spaced. The fifth cusp is small, 

 distinct, and not involved in a crest. There is a small median cusp of the heel. 

 The first premolar has a distinct heel, llie euaniel of the molars is coarsely rugose, 

 a surface which long use does not entirely smooth. !No cingula in one specimen, but 

 in the ty])e and second specimen there is a rather weak one on the external side. 

 The mandibular condyle is entirely above the level of the molars in sp. No. 3. The 

 last inferior molar is not of reduced size. Kamus slender. 



