260 DOUGLASS — FOSSIL MAMMALIA 



Limnenetes platyceps, sp. nov. (Plate IX, Figs. 5 and 6.) 



No. 4.9. 



This is the skull on which the genus Limnenetes is founded. 



Though the teeth are much worn it can be seen that the last two premolars arc 

 small. P s is triangular, and P 4 very short antero-posteriorly. The skull expands 

 rapidly just anterior to the orbits and continues nearly the same width to the post-glenoid 

 processes, giving this portion a rectangular aspect as seen from above. The anterior part 

 of the nose is gone, so that only the posterior parts of the nasals are preserved. 



The naso-frontal suture is short. From the naso-maxillary suture it extends back- 

 ward and slightly inward, then nearly transversely to the median line, not forming a 

 wedge. The nasals arc narrow — not so wide as in Oreodon gracilis. They are flat on 

 top as far as seen. The anterior lachrymal suture is nearly a semicircle. The lach- 

 rymal pit is shallow, and, with the orbital border just behind, is rugose. The supraorbital 

 foramina are small and open a little less than one-third the distance from the frontal 

 suture to the supraorbital border. The channels from these sweep forward and slightly 

 inward, then outward and downward over the face, then backward to the infraorbital 

 foramina which open above P^. 



The frontals, though nearly flat, are slightly concave between the orbits with a low 

 convexity along the frontal suture. Between the channels from the supraorbital foramina 

 the surface is flat, but outside these convex. 



The orbits are much larger than in Oreodon gracilis. They are circular and their 

 upper borders lack only the thickness of the frontals above of being as high as the frontal 

 pl anc — j n f ac t they are about on a, level with the slightly depressed median part of the 

 frontal region. There are postorbital processes to the frontals and jugals, but they do 

 not nearly meet, but end in points about 5 mm. apart. 



The temporal ridges, beginning on the postorbital processes of the frontals, converge 

 rapidly, then with a gentle backward curve meet about in the plane of the; anterior 

 borders of the glenoid surfaces. The parieto-temporal sutures follow these ridges for a 

 little distance, then converging more rapidly form a wider angle in front of the stephan- 

 ion. The sagittal crest is low, being highest just back of where the temporal ridges 

 unite. Hack of this it descends and becomes very low in front of the inion. A narrow 

 median groove can be seen nearly the whole length. Tin; inion is low — a little three- 

 cornered area much lower than the frontal plane. Measuring from a line in the plane of 

 the palate, it does not extend farther posteriorly than the occipital just above the foramen 

 magnum. 



The brain-case is full and well rounded out. It is broadest midway between the 



