i. 275 
1871.] [Cope. 
Both guadrate bones are preserved nearly entire. They have the same 
general character as those of H. icteriews and H. corypheus, resembling 
rather the latter in the great length of the posterior hook, which is with- 
out posterior marginal button. The proximal external angle is large and 
obtuse, and is continued into a prominent thick ridge. The latter divides 
below, the thick extremity turning inwards and ceasing ; an acute ridge 
putwards and joining the exterior acute extremity of the dis- 
is- broad and thick, and not 
‘le forwards on the 
continuing 
tal articular surface. The submeatal knob 
prominent, and its extremity turns at an acute ang 
1encement of the gi ala. The articular 
inner face and forms the com 
expansion on a tuberosity on the 
surface is straight cr : 
outer face (concave of crescent). The meatal pit is sunk between the 
s surrounding, one of which is on the outer margin of the posterior 
= 
hook. 
The mandible is nearly perfect. The dentary bone bears thirteen teeth, 
irections, and not prolonged 
> which descends from the 
and at the extremity is contracted in both d 
beyond the base of the last tooth. The ric 
cotylus along the inner face of the articular bone, is not nearly so strong 
as in the H, mudgev. 
M. 
Length axis with odontoid.......-.-.+-.+++ sees sees 0.062. 
Elevation neural spine of do. at middle.......... 046 
Length third cervical (body).....---+.-.-s+sseee reese: 05 
Se 
Diameter ball ‘ he 
Length posterior dorsal...........0..sse sees eee cece .065 
Diaaneter bull | Teeiiad viata. povvows tesa ot Oe 
Length basis cranii... 06.0... 02sec eee eee -O8 
by BUSPONSOMUML © 64 ss esi ty eee eee es 105 
Elevation occipital crest above floor foramen magnum. .045 
Length tooth line pterygoid..........--..-+-seeee eee 115 
= WARIIATY DOME ai ews ee y eten ees cee 221 
premaxillary laterally... .... ate ug er erga .085 
Width de oC Bl BeCOnG LOOtR. wath vane 041 
Length dentary:...0.0-.-- 24 cers ese tees ieee. 245 
“ maxillary toOOth..... o...se... ses sbiwan ses O80 
ws wee OPO WEL OLLLY xs si onet's 0s oe woe sn 023 
bk os quadratum............ ee or Eon 077 
Width ‘ = ISTH v0 Suu os oy re 045 
Length parietal...... OR Ges ee ee ee 085 
se frontal-to nares (Median)... se... es ev sad 
Width «¢ ‘between orbits........ Si eneedas Core ene O77 
Total length of cranium (18.75 inches)..... se geass eee! 
The specimen above described was found by the writer on the denuded 
foot of a bluff on the lower part of Fossil Spring Cafion. The posterior 
part of the cranium with several vertebree were found exposed, and many 
