1881.] 4yd [Cope. 



rior molars, if they are properly identified ; and in the superior molars. 

 The anterior transverse crest of that genus is represented in Protogonia, 

 but not the posterior. This is replaced by a low ridge running across the 

 course it pursues in Hyracotherium. The posterior median tubercle is also 

 not found in the latter genus. Protogonia differs from Limnoliyus in the 

 subconic character of the external lobes of the superior molars. If the tu- 

 bercles, excepting the posterior inner, should be converted into crescents, 

 the genus Meniscotlierium would be produced. 



Char. Specif. Probably two specimens ; one supporting three superior 

 molars ; the other including damaged superior molars and the last two in- 

 ferior molars. The animal was about the size of the red fox. The exter- 

 nal cusp of the fourth superior premolar is flattened externally, and has a 

 small lobe on its posterior edge. The inner tubercle is conic and is sepa- 

 rated by a tubercle from the anterior base of the external. True molars 

 without external ridges. The external cusps of the true molars are lentic- 

 ular in section. The posterior inner cusp is in nearly the same antero- 

 posterior line with the anterior, its section about equaling that of the 

 intermediate cusps. The first and second molars have an external, an 

 anterior and posterior, but no internal, basal cingula. The enamel is 

 somewhat wrinkled where not worn. 



The heel of the last inferior true molar is elevated, and its worn surface 

 forms the extended posterior branch of the posterior V. The posterior 

 edge of the penultimate molar is elevated and curved forwards on the in 

 ner side of the crown. The anterior cusp forming the angle of the V of 

 this tooth, is higher than the posterior angular cusp, but the anterior limb 

 descends rapidly as in Goryphodon. A weak antero-external, and postero- 

 external cingula. Enamel wrinkled where not worn. 



Measurements. M. 



No. 1. 

 Length of bases of three superior molars 025 



_,. ■ , „ _( anteroposterior 00(36 



Diameters of superior P-m. IV < . „„„„ 



( transverse 0086 



_,. „ ,, T c anteroposterior 0085 



Diameters of superior M. I < ^ „^ 



(transverse 011 



-„. . ,, TT (anteroposterior 009 



Diameters superior M . II < n4 _ 



t transverse 011 



No. 2. 



Length of bases of last two inferior molars 0225 



„. „, . . „ . . c anteroposterior 0114 



Diameters of last inferior molar < ._„„ 



( transverse 0066 



-r.. ,.,,'.,„ (anteroposterior 0112 



Diameters of inferior M. II < _„„„ 



( transverse 0080 



Depth of ramus at M. II 0240 



Thickness " " " 0110 



Meniscotheeixjm terr^rubr^e, sp. nov. My specimens of this species 

 embrace the dentition of several individuals. 



