170 TROCEEDINGS OF THE ACADEMY OF [1883. 



small columnar heel. Fourth premolar with the posterior pair of 

 crescents only, which soon unite. The anterior pair is repre- 

 sented by a part of the external one, which forms a narrow lobe. 

 The heel is larger than in the true molar. 



The position of this genus it is impossible to determine from 

 the specimens in my possession. It may be Marsupial or Con- 

 dylarthrous, and if the latter, one of the 3Ieniscotheriidse ; but if 

 not of these groups, its position is not likel}^ to be in an}' known 

 order of the tertiary periods. 



Char. Specif. — Crowns compressed, deeply grooved at the points 

 of junction of the crescents. This is effected by a narrow 

 lamina from the anterior inner to the posterior outer ; the 

 anterior outer being free posteriorly, excepting after considerable 

 wear. A groove on the external side of the crown distinguishes 

 the heel, which sinks into the crown below. It is lai'ger on the 

 tirst than on the second molar. The heel of the fourth premolar 

 is elevated on its posterior edge. No cingula except a weak one 

 at the exterior base of the posterior lobe of the true molars, and 

 at the anterior base of the anterior lobe of the fourth premolar. 

 Ramus compressed ; but little of it preserved. Diameters of p. 

 m. iv. : anteroposterior, -0055 ; transverse, '0020 ; of second true 

 molar : anteroposterior, -0045 ; transverse, "002. From the lower 

 red bed of the Upper Puerco epoch. D. Baldwin discoverer. 



July 10. 

 Mr. Charles Morris in the cliair. 

 Twent}' -eight persons present. 



A paper entitled " Preliminary Observations on the Brain of 

 Amphiuma," by Henry F. Osborn, was presented for publication. 



July 17. 

 Rev. Henry C. McCook, D. D., Vice-President, in the chair. 

 Sixty-two persons present. 



July 24. 

 Mr. John H. Redfield in the chair. 

 Fourteen persons present. 



July 31. 

 Mr. J. H. Redfield in the chair. 

 Eleven persons present. 

 The following were ordered to be printed : 



