48 PATAGONIAN EXPEDITIONS: PALEONTOLOGY. 



LiCAPHRIUM PYNEANUM Sp. nOV. 

 (Plate VI, Figs. 1-2.) 



Among the fossils collected by Mr. Hatcher at Lake Pueyrredon is the 

 incomplete skull and mandible of a Licaphrium, different from any that 

 has yet been described. Associated with the skull are the femur, tibia 

 and part of the pes. The remains are those of a young animal, with 

 almost unworn teeth ; the premolars are all in place, but the last molar, 

 above and below, was just in process of eruption and not yet in use. 

 Actually, the teeth are of nearly the same size as in L. floweri and are 

 therefore considerably larger in proportion to the size of the skull. In no 

 other specimen of the genus have I seen perfectly unworn examples of 

 p- and - and am therefore unable to make an exact comparison of these 

 teeth in the different species. In p- the transverse diameter is relatively 

 somewhat less than in L. floweri and the other preceding species : it has 

 a single, large, cordate external cusp and a low, ill-defined internal one ; 

 the inner cingulum forms two discontinuous loops, of which the anterior 

 curves backward to the apex of the deuterocone, while the posterior one 

 curves forward inside of the latter, extending beyond the end of the ante- 

 rior loop, but quite widely separated from it transversely. 



The third upper premolar has a more nearly square crown than in L. 

 floweri and the inward projection of the antero-internal portion is much 

 less prominent ; the conules are small, especially the posterior one. Ante- 

 riorly the cingulum is a low, broad shelf, the inner end of which curves 

 backward and dies away against the base of the deuterocone, while the 

 posterior cingulum is much more elevated and rises to join the apex of the 

 deuterocone. A minute, incipient tetartocone arises from this cingulum ; 

 I am unable to say whether this minute cusp is present in other species 

 of the genus, but its variability is shown by the fact that, in the individual 

 before us, it is more distinct on the right side than on the left. 



The fourth upper premolar, like p-, has a more nearly square crown 

 than in L. floweri and, in particular, the inward production of the antero- 

 internal portion is less, so that the tooth has a more symmetrical outline : 

 the conules are larger and more conical than in p- and the posterior cin- 

 gulum is separated by a cleft from the deuterocone. On the right side, 

 there is no tetartocone, as in the other species of the genus, but on the 

 left side, there is an extremely feeble indication of it. 



