1878.] 525 {[Cope. 
which is a short vertical and compressed angular process, which is round- 
ed in profile. There is a patch of small teeth inside of the posterior ex- 
tremity of the mandibular series. The mandible closes inside of the pos- 
terior part of the quadrato-jugal arch. There is a groove near the inner 
margin of the inferior face of the mandible ; external to this the surface is 
marked with elongate shallow pits. The sculpture of the external side of 
the ramus is less pronounced, and the pits are smallest near the angle. 
The pits of the top of the cranium are coarse and well defined. The frag- 
ment of maxillary bone is broken off four teeth behind the tusks, and the 
neural opening has contracted but little at that point. The sculpture of 
the anterior portion of the maxillary is coarsely reticulate. 
The diapophyses of the centrum are oblique rhomboids in form, the an- 
terior upper side receiving the neural arch. The external surface is con- 
cave and smooth. The median element, which I call the intercentrum,* 
is a crescent with subacute horns, which terminate below the anterior part 
of the posterior zygapophyses. The inferior surface is slightly angulate, 
with two low latero-inferior ridges, and sometimes a low median one. The 
surface between them is delicately reticulately sculptured. The neural 
arch is oblique and highest behind. The combined neurapophyses rise 
rather abruptly behind the anterior zygapophyses with an obtuse and con- 
vex margin. They then descend in an arc to the extremities of the poste- 
rior zygapophyses, diverging downwards and separated by an open groove 
which was doubtless the basis of attachment of the cartilage which repre- 
sented the neural spine. External surface of the neurapophyses smooth. 
The zygapophyses have little lateral expansion, but are well defined and 
prominent antero-posteriorly. The processes which I have alluded to 
above as diapophyses, may not be such, as they are simply transverse ex- 
pansions of the anterior inferior portion of the neurapophyses, whose pos- 
terior border articulates with the lateral diapophyses of the centrum. 
The basioccipital condyloid fossat is transversely hexagonal in outline, 
the superior border being deeply notched by the superior portion of the 
fossa chorde dorsalis. ‘The articular surface itself is funnel-shaped. The 
parasphenoid bone advances far posteriorly under the basioccipital. It ex- 
pands into an acute angle on each side below the prodtic, and then con- 
tracts, so that its sphenoid region is narrower than its occipital extremity. 
Its surface is slightly concave. 
Measurements. M. 
Depth of maxillary bone at middle of nares............ -021 
Width of palatal surface He Ce eee nema 0) 2 
Six maxillary teeth ee (ON VS. Q@GHnc oe ene 014 
Diameter of an anterior maxillary tooth............ Soe UU 
as He fUSk: OL INNEL POWs cesens cccse< O04 
Length of ramus mandibuli to anterior border of inter- 
nal pterygoid fossa...... Legadbeadosuussesdceae sade alee ODS 
Depth of do. at do..... oh ksi Sis Wace Shonen aonene 023 
* American Naturalist, May, 1878, p.328 
+ This term is used as preferable in this case to that of occipital condyle. 
