318 MEMOIRS OF THE CARNEGIE MUSEUM 
tocone, which has received very little wear on account of the absence of p;. There 
are no cingula, except on the anterior and posterior angles on the internal side. 
The tooth is implanted in a single alveolus. The two roots are closely coalesced, 
with a groove indicating the separation of the roots in the species of earlier Tertiary 
times. The premolars and molars back of p* are so badly worn that they present 
no characters capable of description. 
The fragment of the lower jaws which belongs to this specimen (No. 1418) 
indicates an animal somewhat larger than the type. The ramus is somewhat 
deeper and the diastema back of the canine is longer than in the type specimen. 
The diameters of the teeth are practically the same as in the type. The principal 
features of the fragment are the solidly fused chin and the absence of p,, showing a 
correspondence to the tvpe. The canine reveals a long abrasion on the antero- 
external angle which has removed part of the enamel, forming of the remaining 
enamel a diamond-shaped surface at the.summit of the tooth. 
MEASUREMENTS. 
Length of skull from supraorbital foramen to end of premaxillaries ............. 200 mm. 
oe“ “~~ infraorbital foramen to end of premaxillaries 
«« “alveolar border from m! to end of premaxillaries..... ...............206+- 
Antero-posterior diameter of the incisors ................2..22seceeseeee cece ee cece eeu eeees 
Di aa antero-posterior 
iameters 0 
UWA TASETEcon000 caqgsovododsebs banDsocNgbEsAd0 HoocoAdODRDOKca"GC0 9 
. ce 
he “ p antero-posterior 7 
ETANSVELSC ecccs ons ereoceenecatenceasn-taecencteatcee eeeaccanore mene Gs 
7 “ec 
‘ie “qs ANGEETO POSLETIOL...........0ce-cecesceesersceccsccec seers cececesssenssesecs 55 
Gransverse ys. scos reece neces Rcjevaie se dlastenteee sovvaractoees yr 0 
Ai ms : amter0-POSteriOr ............-0eeccee cecscseeeeaeeeaeeeeees 4s igs 
canine at base an 
GIANSVETSC lee. vee scoeeoracese cescccec eee comnaeteetecee 10 
+ ce 
Pr es antero-posterior... 6 
UREIRSK(E37313) cono0cp50000000005000K00 e000 0ce000500000000000000000000500300000 Ae 
“ “ 
7 re ANFETO-POSTETION.............ceceeeeresrerees teerecsersececscsessessrenens 13 
HANS VETSC $ sicvacscccecssaeessssucsesGmscseecuetsdnacsuseves esecvoeeeeweery 10 ‘* 
DISCUSSION OF RELATIONSHIP. 
It will be safest to await the discovery of more perfect material representing this 
group of Miocene peccaries before expressing a positive opinion as to their affinities. 
There are two types of the genus Thinohyus, a dolichocephalic and a brachycephalic. 
Professor Cope separated Thinohyus decedens, generically from other John Day 
forms, giving as the principal character the absence of p?, which is found to be 
erroneous.” Judging from the description by Cope and Sinclair, and also from the 
°Sinclair, Bull. Dept. of Geol., Cal. Univ., Vol. IV., p. 135, 1905. 
