from the Miocene Deposits of Balucliistan. 407 



munis (Cong. Sci. FrarKj.. 1885), the generic name Amphi- 

 tragulus being changed to Gelocus without comment or 

 diagnosis. 



The present specimen, a third upper moh\r, tlierefore is 

 placed provisionally in this genus, relying on the characters 

 given by Lydekker as follows: — 



"The upper molars ot" this genus have extremely low 

 columns with wide open valleys; the external surface of the 

 hinder lobe of each of the outer columns is markelly concave," 

 &c. (Cat. Fo38. j\Iamm.). 



This tooth shows all these characters and in general plan is 

 similar to a corresponding tooth of Gelocus communis in the 

 British Museum collection (m. 27596) *. 



Fig-. 3. 



The specific differences from it of the present specimen 

 are : — 



1. A greater concavity of the external face of the metacone. 



The posterior horn of tlie cusp runs down to the 

 cingulum and then turns forward as a sharp ridge to 

 join the mesostyle, whicii turns back to meet it at the 

 middle of the cusp, the two forming a '* cingulum " 

 ridge with a noticeable ditch between it and the body 

 of the cusp. 



2. The posterior horn of the protocone does not abut 



against the metaconule (hypocone, according to some 

 authors), but turns sharply forwards, leaving a deep 

 groove between the two internal cusps. 



3. The cingulum is well marked only at the front border 



of the protocone and in the valley at its posterior edge, 

 t. e. between the two internal cusps. In G. communis 

 it is continuous round the cusp. 



4. The tooth is larger than that of Q. communis and too 



small for Pilgrim^'s specimen (a lower molar) of 

 G. gojensis. 



* This specimeu, by an error, is catalogued as a lower jaw. It is an 

 upj)er jaw. 



