A MK.'IOlli rroN THE (iKNU.S 
.J7I 
ol tlu- ..iit.-rioi- an.l til.- aut.-ri.ir <-ivst of tlio posterior V in contiimitv internally, 
p t.-rior tiilK-r.-l.- of last inferior molar always iiresent. Manns of the paraxonic 
iZ- with four funetional .li/'t*^- nt'^rly 
M.l-smal i.ia.m.im ami nn.-if..nn fiieets. ami eonse.piently scaphoid widely separated 
MilMspial iiiafriiiiiii 
from iim-iforiii. Mafriuiin small. _ 
,.„|..„m-al faeols jr.-m-rally widely separated. A large astragal.Kiuboid contact. Fils 
IVs with three wide .spreading digits. Astragal.s 
<-alcam-ai im-.-is s' • • i in, i . 
ul.M-al.-am-al facet pivs«-nt. Navicular hroad and l(jw. Metatarsals of the alternat- 
*\s aln-a<l\ |)ropo.se«l. the family Titanolheriicice maybe divided into two sub- 
fainilies with the foll.iwiiig defiiiitioii.s. 
A. Nom-ofthe pi-emolai-s molariforin, Pal.ko.syoplv.e. 
H. Sane of the pi-.-molars molariforin, Titaxotheriix.e. 
C.euentl Chatackrs of the Palcrosyopinee. — Dentition.— i.| c.{, pin.J, ni.i 
The siihfamily l\il<eosyopht<c is distingnished above all from that of the Jitan- 
otheriitur by the simplicity of the premolar.s, and in none of the genera are any of 
ihcM- l.s-lli as e.aiiple.x in their structure as the true molars. Only in the highest 
genus of this sulifainily. namely Telmatotherium, do we find any signs of the 
pn-iiiolars taking .ai the .-haraeters of the molars. Then again in this sub- 
family. all its im-udM-rs as liir as known have a full complement of both upper and 
lower im-is4irs. and al.so the canines are very much developed, much more so com- 
pansl with the size of the animal than in the other subfamily. The first superior 
pn-iiiolar is a double faiigi-d t.Kith. with or without heels; the .se.-ond tooth of the 
M-ries alM»\e may havi- its iuternal cone rudimentary. The last two upper premolars 
an* alwa\s Irieouate in struct iir.-. As a rule the bust sujierior preniolar is much 
smaller than tin- first su|M-rior imdar. This rule applies especially to the more prim- 
itive tueiiilH-rs of this subtiuuily. 'I'he variation in the details of the molars in the 
iliflen-ut gi-u.-ra is eoiisideralde ; and when we comjiare the undiflerentiated molars of 
/^imbitoihenuni \\\\\\ those of 7'e/>naiothe)'jum,\\ {i can appreciate the great specializa- 
tion of the one gi-iius ov.-r the other. This ajiplies e.specially to the develop- 
im-nl of the external V’.s, ami the crowns of the teeth. In Lambdotherium the V’s 
an- shallow ami the external cusps of the .same show strongly their original bunodont 
ehanieter. I he eniw ns ol the molars in this genus are very low. On the other 
haml. in l\tt<rosyops the.st* characters become more .specialized and progressive; 
w hen-as in 7'etiuotothenum the characters of its molars approach more nearly those 
of I'ttonolheriuni. and an- intermediate in character between the latter genus and 
/ okrosyops. In tin- lower genera the external cingulum of the true molars is 
"anting. In /'ehnatothenmn the external cingulum is a verv conspicuous character 
ol the inolai-s. I he intermediate tubercles are variable in this .subfamily, and we 
«an taifely .sav- that a.s a whole the less sjiecialized genera, such as Lambdotherium 
nm^ akrosyops. have thegn-atest development of the intermediates. This is specially 
noti«-<a ill in Lombdothcnunt when* the development of the protoconules has gone 
