_ ^ M KM 0 1 R UPON TI I E GEN US 
I «• r ,1 iMKliiiiciitarv More accurately speaking 
Minnll iH^U-rior cone t mih foriiimg ^ dLeneration. If this view is correct 
i. i. .I..., .i.n„ 
I «i>ulil r.'P«nl ” „,„„iti„nal stage between tlie latter si}ecie» 
.,.,1 I..M,rfs. „ this series the last n.nlar law a 
„„ .,.,v in.en....ng premolars am higher than in the 
r“' Trlu The'toi ill. of this mries is not separated by a ...edian bnitress 
,i’!!!p.,ien.llv the ca«- in P. paiudosus, while the second and third preinolars have 
“Jnnnlele internal cingula, a character confined to the higher genus rdmato. 
Ihrrium. Uon«M,nently in this variety we see two lines of variation : one tending 
lownni Umnohyops ami the other toward Tehnatothernini. . ... 
Then- is n very interesting lower jaw in the collection, No. 10,018, in which 
the .-ones of the ino'lars aiv higher than in the typical form. This applies especi.a ly 
to molar .S. when- the crown is very narrow and the iiosterior tubercle unu.sually 
Urp- for this s|s-eies, lH*ing as hroa.l transversely as the Avhole crown of the tootli 
in fnait. while in the typical form this tnkwcle is merely a cone. The variation in 
the clianicter of the dentition of the akive jaw would lead us to consider that tins 
is a variety l«-inliiig towanl Telnialolherium, as indicated by the elongated and 
incn'aMsI height of the cniwiis of the last molar. 
Pa/tfoSYops l<n'idens is pmlmhly lower in phylogenetic position than P . pahidosus, 
ns its su|H>rior pnaiiolar 'i has only' one e.xternal lobe and this tooth is simpler than 
in any other sjsH'iesof this subfamily. The intermediate tuhercles of P. l<evidcns are 
nsliicisl ; its lust su|H*rior molar exhibits a .small cone at the po.sterior internal angle 
of the tiMith. One character of the skull of P. Icevidcns, to he de.scrihed later, 
indicate that the sjMM'ii's is inoi-e closely related to L. laticeps than to P. paludosiis. 
In the chariiclers of its skull /*. mcgarhinus dejiarts widely from P. pa/udosus, but 
its rather low erowueil molars without external cingula indicate that it is. perhaps, 
nioiv closely ndated to the hitter sjK*cies than to any other, although its cranial 
characters show it to Is* an alierrant form of the genus. 
Pnif. (*o|H* s P. valUdcMs is a very' interesting species, and its dental characters 
indicate that it ought to lx* jihu-ed near Tclmatothcrmm. This is pi*oveii by 
the characters of the lower molars which have high and elongated crowns, thus 
ilepaiting widtdy from the molars of P, paludosiis, although the species shows its 
el.ws> afliuity to the hitter in the cone-like form of the posterior tulx-rcle of 
inferior molar X TIu- characters of the jaw of P. vallidens are clearly Tehnato- 
Iheroal. The pliylogem-tic isisition of P. vallidens is therefore between P\ paludosiis 
TchiaMhrriuni. although as a whole this species shows closer relationshiii to 
the latter genus. 
I n.pinl />. mimr „« Whig iiuicli more closely rclnte.1 to Telmalollicrium 
limn I,. /. 
'TiT«i«r)- ViTlehnitii, platp LI. Hit. 2. 
