were two cusps because the cingulum is still so high (as high as the outer edges of the paracone and metacone) as to suggest that it is only slightly worn. Posteriorly this single cusp in the cingulum is united with the hypocone. Anteriorly the cusp is confluent with an anterior cingulum that is small, but, nevertheless, plainly visible as it crosses the occlusal face of the tooth to the paracone. There is some reason to believe that there was a posterior cingulum, but wear, which has obliterated even the posterior wall of the hypocone, prevents my being certain about this. This cingulum is absent in _H. gregoryi_ and present in _H. hatcheri_. M2 compares favorably with M1 except for the following differences: The protocone and hypocone are equal to the paracone and metacone in area, but not in height; although the internal cingulum is undivided, there is no evidence of a cusp as in M1. Here, too, the cingulum is as high as the paracone and metacone. Possibly the cingulum was confluent with the hypocone. The internal cingulum continues around the margin of the tooth to the paracone as an anterior cingulum which is sharper and plainer than the anterior cingulum on M1. There is no evidence of a posterior cingulum. M3 shows a great amount of wear, and the occlusal pattern is not too clear. The median transverse valley is reduced almost to a pit, and the paracone and metacone are divided by a small notch. The protocone and paracone, the latter being much higher, are larger than the metacone which is reduced in size, and not all this difference in size can be the result of wear. The hypocone is absent. The internal cingulum is as high as the paracone and shows no evidence of division into two cusps, but in M3 this character is apparently variable for _H. gregoryi_ does not have the internal cingulum divided and _H. hatcheri_ has it markedly so. A slight anterior arm of the internal cingulum may have reached forward to the anterior face of the protocone. Wear prevents knowing whether a crest surrounds the tooth completely, or only on three sides.