XII CONTENTS 



Figure Page 



234. Lower premolars of three "species" or mutations of Lambdotherium 282 



235. Upper and lower grinding teeth of Lambdotherium 283 



236. Lower jaws and teeth of Lambdotherium popoagicum 284 



237. Lower jaws and teeth of Lambdotherium popoagicum, side view 285 



238. Front part of type lower jaw of Lambdotherium priscum 286 



239. Incomplete lower jaw of Lambdotherium priscum 286 



240. Jaws and teeth of Lambdotherium priscum and L. magnum 287 



241. Lower jaw and teeth of Lambdotherium progressum • 288 



242. Upper teeth of Lambdotherium progressum 288 



243. Restoration of Eotitanops borealis 289 



244. Skulls of the oldest known titanotheres, Lambdotherium popoagicum and Eotitanops borealis 290 



245. Model of skull of Eotitanops gregoryi 291 



246. Lower premolars and molars of Eotitanops 291 



247. Lower jaws of Eotitanops gregoryi and E. brownianus 292 



248. Lower jaw of Eotitanops borealis 293 



249. Lower teeth of Eotitanops borealis 294 



250. Skull of Eotitanops borealis, palatal and side views 294 



251. Skull of Eotitanops borealis, top and occipital views 294 



252. Lower jaw of Eotitanops princeps 296 



253. Lower grinding teeth of three species of Eotitanops from the upper Huerfano formation 296 



254. Skull sections of brachycephalic and dolichocephalic Eocene titanotheres 299 



255. Cross sections of the skull m middle Eocene titanotheres 300 



256. Three skulls typical of the palaeosyopine group 301 



257. Distribution of Palaeosyops and associated fauna in the Bridger formation 301 



258. Anterior part of skull of Limnohyops laevidens 306 



259. Skull of Limnohyops priscus 307 



260. Back part of skull of Limnohyops priscus 308 



261. SkuUs of three species of Limnohyops 309 



262. SkuU of Limnohyops matthemi 309 



263. Skull of Limnohyops monoconus 310 



264. Skull of Limnohyops laticeps 311 



265. Third right upper molar of Limnohyops laticeps 311 



266. Lower jaws of Limnohyops and Palaeosyops 314 



267. Lower jaws of Palaeosyops 314 



268. Lower jaws of three species of Palaeosyops 316 



269. Young skull of Palaeosyops fontinalis 317 



270. Upper molars of Palaeosyops fontinalis 318 



271. Teeth of Palaeosyops fontinalis 1 318 



272. Skull of Palaeosyops major 319 



273. SkuU and head of Palaeosyops leidyi 324 



274. Incisors and canines ot Limnohyops a.nd Palaeosyops 325 



275. Skull of Palaeosyops leidyi 326 



276. Type skull of Palaeosyops leidyi 327 



277. Type skull of Palaeosyops leidyi, top view 328 



278. Type skull of Palaeosyops leidyi, palatal view 328 



279. Skulls of Palaeosyops major and P. leidyi 329 



280. Lower jaws of Palaeosyops leidyi : 330 



281. Skulls of Palaeosyops leidyi and P. copei? (aff. P. robustus) 331 



282. Jaws and deciduous teeth of Palaeosyops leidyi? 332 



283. Deciduous cheek teeth of Palaeosyops leidyi? 332 



284. Fragments of jaws of Palaeosyops 333 



285. Skull of Palaeosyops robustus 333 



286. Hyperbrachycephalic old male skull of Palaeosyops robustus 334 



287. Basicranial region of Palaeosyops robustus 334 



288. Nasals of Palaeosyops robustus 335 



289. Progressive hypsodonty of the molars in Telmatherium 341 



290. Upper jaw of Telmatherium cuUridens 342 



291. Upper and lower teeth of Telmatherium cultridens 343 



292. Upper and lower teeth of Telmatherium cultridens, interlocked 343 



293. Lower jaw of Telmatherium cultridens 344 



294. Type skull and lower jaw of Telmatherium ultimum 346 



295. Type skull of Telmatherium ultimum, side, front, and occipital views 347 



296. Type skull of Telmatherium ultimum, palatal and top views 348 



297. Paratype skull of Telmatherium ultimum 349 



298. Lower jaw of Telmatherium ultimum 350 



299. Hypothetical reconstruction of the skull of Telmatherium altidens 352 



300. Lower jaws of Telmatherium ultimum and T. altidens 353 



301. Type skull of Sthenodectes incisivus . — 356 



