148 University of California Publications in Geology [Vol. 10 



verse ridge is formed as in Megalonyx. This ridge swings outward 

 and downward and in some skulls is directly connected with the pos- 

 terior surface of the stylohyal process. The crest of the occiput is 

 not prominent except along its lower end. 



< < < < ■< <i 



co g co g te g co g cog cog 



• u • u • u • u ■ u < u 



KM Wee Em Km Mm 



Measurements of Cranium g ■ a Uu s £^ a S^-a a « 



gSj cSj crfj sS^j 



CO O IcCOc to CO o b p1 O w^O m^O 



cs co ds o xl n ~ c;co^: rt^x: <3 co ,n 



X H O ^ L' ,i= CO Cj x- CO U r-CCO CO C 



» . « to . a m.c » . c m.c IZ.c 



.©« .Oct . o ci . o ee .ocs .oca 

 fe^CS fcfctf 



Length from anterior end of maxillaries to 



posterior end of occipital condyles 320 mm. 309 302 313.6 330 



Length from anterior end of nasals to pos- 

 terior end of supraoccipital 339.8 336.3 320.4 333.3 339.5 352 



Length of palate, from anterior end of 



maxillaries to postpalatine notch 141.7 0135.4 127 131 144 



Greatest width of palate anterior to M2 45.8 46.2 42.9 42.9 48 



Width of palate between alveoli of M.- 22 23.6 21.4 20.6 24 21.8 



Greatest width of pterygoid bulla 41.4 43.2 17.4 o37.9 37.4 a41.6 



Greatest length of internal orifice of ptery- 

 goid bulla 37.6 38.2 21.7 36.7 30.5 



Greatest width of internal orifice of ptery- 

 goid bulla 14.4 a8.5 12 



Least distance between pterygoid bullae 



Mastoid width above stylohyal processes...- 112.8 118.4 



Greatest width across occipital condyles .... 75.4 78 



Transverse diameter of foramen magnum, 



internal measurement 33.5 29.6 



Dorso-ventral diameter of foramen mag- 

 num, internal measurement 28.7 24.9 



Height of oeciput from plane of basioccipital 



to lambdoidal suture 79.6 87.7 



Greatest width of muzzle at anterior end.... 70 78.2 



Length of nasals 114.5 114.7 



Greatest width above orbits 103.2 104.9 



Least width behind orbits, in region of 



coronal suture 78.2 80 



Width, measured across anterior ends of 



zygomatic processes of squamosals 153.8 153.5 



Least distance between outer sides of ptery- 

 goid plates 61 56.4 



Greatest height from ventral border of ptery- 

 goid plate to highest elevation of frontals 134.7 139.9 a!30.3 



a, approximate. 





23.3 



21.3 



21.8 



110.5 



114 



114 



120.6 



78.4 



74.9 



78.4 



81.1 



30 



32 



31.8 



36 



26.3 



24.2 



24.2 



29.5 



80.7 



78.5 



76.5 



85 



65.5 



73.9 



73.4 



73.4 



130.8 



111.9 



134.3 



122.4 



98.3 



104.3 



102.9 



112.9 



82 



78.5 



77 



83.8 



MANDIBLE 



The most striking characteristic of the lower jaw of Nothrotherium 

 is its great similarity to that of Hapalops. The former genus in this 

 regard is decidedly closer to the Miocene form than to its Pleistocene 



