THE SKULL OF PALEORHINUS 147 
Furthermore, the proportions of the skull are quite different. The 
following table of dimensions will serve to make this clear: 
Mystriosuchus Paleorhinus 
planirostris bransont 
Wemethvoteskulle scree oe cits citeele ed whee eine 33.375 inches 30.500 inches 
Width of skull across quadrates............... PSS a OE 7SOme i 
Width of skull opposite middle of orbits........ 6.625 “ Ago. 
Width opposite anterior extremity of external 
TAN CS ee Pace uti shee eran ee aope rs es abate yee BrOOOn BOOOn a 
Length from rear of skull to quadrate.......... Te 5OOh ue: OnBOOr= 
Length from rear of skull to lateral temporal fossa 2.875  “‘ 29875 meee 
Length from rear of skull to supra-temporal 
LOSSAEAMLCTIOMPEXUTCMI Ly amy en ine sey eee Diogo Bayicon. t 
Length from rear of skull to supra-occipital.... 1.375 ‘“ 2B OOM aide 
Length from rear of skull to rear point of orbit.. 4.400 “ FOOO suas 
Length from rear of skull to rear point of pre- 
Oni taleVaCUlby ss. Comm se Sin ise im chives Ge7Son hs (sigustorey ot 
Length from rear of skull to rear point of nares.. 8.000 ‘“ TOE OCR 
Length from rear of skull to anterior point of 
INUKe Suse rata cee h MP Aent Po. en eels ay Maran On5COn t= TAVOZ Ge iis 
Length from rear of skull to rear point of inter- 
WA MATES meee tas lect Mep haere ast aNapa are SrOCOm 7a) (ajatcleloy 
Wenethkotprentasdllareeeceme tari. ie eeyy ts ook 222500 ak WANS Oe 
WWemouheomrnaxillay ees asa ei ose sien TS OOM tne WAR SOO/ er) 
Menetheofmasals eae wes cation ray whe eee ee ae ea HS O75h lie Oca (2) 
NVatclGlntoten asall sary vested rsa) eecatses Mle l Vere coca bie ite Ng CSO) <9) 
Menethyotstromtalssenass jcee west ee eee 2HOOO as: 4.000 “ 
NWidithvotetromtals} rss s2; i ecs.xsees toe oekoncy tclch ve fiona ne tov «Oe Te OOO mane 
INumberot-teethronsupper jawers .. sac see: 94 72 
There are several other differences, among which may be noted the 
following: In Mystriosuchus the parietals extend backward between 
the supratemporal openings at the level of the top of the skull for 
a little less than one inch, while in Paleorhinus they extend in this 
direction two and one-fourth inches, are widely separated, as already 
described, and meet the squamosals posteriorly to enclose the supra- 
temporals at the upper level of the skull. In Mystriosuchus this 
“parietosquamosal arcade,” to use McGregor’s term, is considerably 
depressed and forms a thin plate lying on the paroccipitals. This 
gives the supratemporal openings and the large median notch quite 
a different appearance in the two specimens. Several of the openings 
in the skull are of different shapes in the two individuals, and the 
