999 
_—— 
MEMOIRS OF THE CARNEGIE MUSEUM 
Most of the fragments of the skeleton are too imperfectly preserved to admit of 
accurate description. 
The centra are injured. 
in position. 
Portions of five of the lumbar vertebree are still united and 
Three of them are 2 cm. in length. 
The tail was long and heavy judging by two vertebree from near the anterior 
portion, and two others farther back. 
measure 2 cm. in length. 
They are as broad as the lumbars and the two 
Two other caudals are preserved; one 1.15 cm. in length, 
apparently from near the middle, and one 1 cm. in length from near the end. 
A metacarpal was found at the same place, but it is not certain that it belongs to 
this specimen. One median and one ungual phalanx are also preserved. The lat- 
ter has a short heel on the dorsal surface and a small one on the plantar portion. 
The species of /ctops thus far secured from the Titanotherium Beds are: 
Ictops thompsoni, I. intermedius, [. montanus, I. acutidens, I. tenwis and I. major. 
The beds are.in some places at least several hundred feet in thickness, being 
several times thicker than in the type locality, but as yet different faunal horizons 
have not been distinguished. 
At least three of the species have come from levels 
not differing greatly in height, probably less than 100 feet, yet of the lapse of time 
between their deposition we know nothing. 
In size the species rank as follows: (1) Ictops thompsoni, smallest, (2) I. iter- 
medius, (3) I. montanus, I. acutidens, (4) I. tenws and (5) [. major. 
P= has four distinct 
and separate cusps. 
| P® anterior cusp very 
| small. Protocone 
| and postero-external 
| cusp connate. 
|P2 cusps Jow and 
| blunt; the anterior 
| one hardly distin- 
guished as a cusp. 
P+ tritocone larger but | P* protocone much | 
not so high as pro- 
tocone. 
intermediate 
between outer and 
inner ones. A strong 
outer cingulum, and 
anterior and  pos- 
Two small | 
cusps | 
| cingulum weak and | 
| higher than trito- 
nal cusp_ small; 
cone ; postero-exter- | 
| antero-external cusp | 
smaller than in I. 
terior outer cingular | 
cusps. 
M+ strong _ postero- 
internal cusp, strong 
cingulum on outside. 
Length of tooth 
nearly equals width. | 
M+ much smaller than 
M2. 
Zygoma not heavy. 
| M1 _ postero-external 
cusp not so large as 
in I.; cingulum not 
so strong; tooth 
wider in proportion 
| to length. 
| M2 proportionally 
| larger than in I. 
| Zygoma heavy. 
| Post glenoid processes 
large. 
| 
| 
M# proportionally | 
larger than in I. or 
Il. 
| Zygomacomparatively 
slender. 
| Post-glenoid processes 
much smaller than 
in Il. 
the three other cusps | 
low and small. 
P+ protocone decid- 
edly higher and 
larger than _ trito- 
cone; antero-exter- | 
nal basal cuspsmall. | 
Cingulum on ante- | 
rior and _ posterior | 
outer portions of | 
tooth. | 
M!  postero-external | 
cusp small; cingu- | 
lum quite strong ; | 
tooth very wide in| 
proportion to length. | 
Zygoma heavy. 
V. Ictops major. 
P2 much as in last 
but larger and cusps 
more massive and 
not so acute. 
P+ anterior and pos- 
terior outer cusps 
small. Cingulum 
nearly surrounding 
tooth ; protocone 
higher than trito- 
cone. 
M® about as in I. 
