86 O. C. Marsh on the Affinities of the Broniotheridee. 
so. It resembles the corresponding tooth in L Prout but the 
inner Beirne angle of the crown is much more develope 
mbs in this species were shorter than those in the exist- 
ing Aachasie which, in form of body, it doubtless resembled. 
The nuge divergent ‘horns, and the absence of tusks, gave the 
head a very different appearance. The one narial opening, 
the rugose extremities of the nasals, and the large infra- 
orbital posites, naturally suggest that there as have been an 
elongated, e nose, possibly as extensive as in the Tapir. 
That there was no long roboscis, as in the Elephant, is indicated 
with equal certainty By the length of the head and neck, which 
renders such an organ unnecessary. 
The principal dimensions of the skull “em in plates 
I and 11 are as follows: 
asurements. 
Length of skull from sean condyles to end of mene 
GerOmOnRndadb 
im 
6 INCROR),.. xan kek jee Gee ew eek i ee ia. 
Distance from posterior margin of occipital crest to ae 
DE SMO, ks ees ea ne ot on 
Distance on median line from occipital crest to end of nasals, 762° 
Width between extremities of horn-cores (20 inches), __.. 507° 
wxipanse of sypomatic arches, 922-2225. 
Least distance across vertex, ..---..--- .... 22.2.1... 157° 
Space occupied by four upper premolars, ___._._.___.-.- 162° 
Space occupied by three upper true molars, .__._.__._..- 266° 
Antero-posterior diameter of last upper molar, on outside, - 117° 
Antero-posterior —s through center, ......-.....2- 112° 
srangverss diameter, MMi ole. ee oc 14° 
Ant wa Last cos amet of fourth upper premolar, - ---- 53° 
Transverse diameter,. ..- 2.20. 252 og ee es se ews 69° 
Anter seers diameter of third upper premolar, -__ .__- 48 
Antero-posterior diameter of second upper Eeamolar, cas 37° 
ntero-pos diameter of first upper premolar, --_- __- 26°5 
Width across palate between second premolars, ___-____- _- 55° 
Vidth across pala e between last upper molars, nuccap eee 115° 
pace between outer faces of last upper molars, - We ihe ce 330° 
rreatest height of “yg0 ccs 145° 
leig of zygoma at anterior or extremity of malar suture, -- ae 
rreatest a of Seagal COUN PUG ee Se 120° 
PS io eae Bon eee ee 75° 
Jistance GC aaieca outer margins of occipital condyles, -.. 204° 
All the known remains of this species are from the Miocene 
oe of gs ak and are preserved in the Yale Museum. 
‘Yale lege, Dee. 24th, 1873. 
tele aarsivers or PLATES, 
‘pate i Brontotheriwm ingens Marsh. Side view. One-sixth natural size. 
Plate I. Srecehwhns Guetta Top view. One-sixth natural size. 
