426 THE PUEllCO EPOCH. 



Protogonia subquadrata Cope. 



Paleontological Bulletin No. 33, p. 493, IS-^l. Proc. Amer. Philos. 8oo., 1881, p. 492. 



Plate LVII/; figs. 11-12. 



Probably two specimens; one supporting three superior molars; the 

 other including damaged superior molars, and the last two inferior molars. 

 The pertinence of the latter specimen to this species is doubtful. The 

 animal was about the size of the red fox. The external cusp of the fourth 

 superior premolar is flattened externally, and has a small lobe on its pos- 

 terior edge. The inner tubercle is conic and is separated by a tubercle 

 from the anterior base of the external. True molars without external 

 ridges. The external cusps of the true molars are lenticular in section. 

 The posterior inner cusp is in nearly the same anteroposterior 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 inner 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 Coryphodon. A weak antero-external, and postero-external 

 cingula. Enamel wrinkled where not worn. 



Measurements. 



No. 1. M. 



Length of base:) of three superior molars 025 



_. ^ , . _ . (anteroposterior 0006 



Diameters of superior P-ni. IV < ' „^^_ 



' < transverse 0086 



_. . , • xf (anteroposterior (XXS.') 



Diameters of superior SI. i < ' 



( transverse Oil 



_,. . - • nr •• ( auti'ioposterior 009 



Diameters of superior JI. ii < . ' 



t transverse Oil 



No. 2. 

 Length of bases of last two inferior molars 0225 



Diameters of last inferior molar J "" "^"^°* "^ " „,.. 



< tr.insverse OOoC 



