325 



In I his view Professor Cope has recently descrilted some remains of I'aln'- 

 os3()[is under the name oi' Liiii/whi/us Iceoideiis. 



Teeth such as I have attributed to Palaeosyops arc comparatively abundant, 

 but I have not yet had the opportunity of inspecting a specimen of a 

 last upper molar, such as Professor Marsh ascribes to Palaeosyops, in 

 which the inner side of the crown possesses two internal cones. That 

 such exist there can be no question, as proved by Professor Marsh's 

 description of Palaeosyops laticeps. 



Professor Marsh has described some remains which he refers to a genus 

 wilh the name of Tehnatherium. Of this, he observes: "The dcniition 

 of til's genus, so far as is known, appears to be similar to that of PalaBo- 

 syops. The upper molar teeth have the inner cones more elevf^ted and 

 more pointed than in Paheosyops, and the Ijasal ridge is well developed 

 The last upper molar has l)ut a single internal cone." He also remarks 

 that " the two may be i-eadily distinguished i)y the anterior portion of the 

 skull, which in Telmatherium has the premaxillaries compressed, with an 

 elongated median suture. The zygomatic arch is also much less strongly 

 developed, and the squamosal portion of it is comparatively slender.'' Such 

 differences are more likely to be of a sexual or individual character than of 

 either specific or generic value. 



Since writing the preceding chapters we have attempted to give a restora- 

 tion of the skull of Palseosyops in' Fig. 1, Plate XXXI, built up from a 

 number of specimens. The cranium and face were mainly reconstructed 

 from the specimens of Fig. 51, Plate XVIII, and Figs. 1, 2, Plate XXIV; 

 the lower jaw from the specimen of Fig. 52, of the latter plate, and Fig. 

 4, of the former plate. 



1. Pal^osyops paludosus. 



Leitly: Pr. Ac. Nat. Sc. 1870, 113 ; 1871,114,197,229; 1S72, 1G8; Hayilcii's 



Hep. U. S. Geol. Sur. Wyoiuiug 1S71, 355; llaydeii's itup. U. S. Geo). Sur. 



Moutaua 1872, 359. 

 Pulmosijops. Leidy: Pr. Ac. Nat. So. 1871, 118. 

 Ijbnnohijus hvvidens. Cope: Pr. Am. Pljil. Soc. 1873, article published in advance 



.January 31, 1873. 



The description of the species is given on page 28 of the present work. 

 The specimens represented in Figs. 1 to 8, Plate IV; Figs. 4 to 11, 

 Plate V ; Figs. 1 to 4, Plate XIX ; Figs. I to 7, Plate XX ; Figs. 3 tp 



