414 HARRIS HAWTHORNE WILDER ON 
Between them is a flattened depression, the internasal fossa, which lodges the internasal 
plate of the chondrocranium. The dorsal side possesses few features of interest. “At the 
anterior end is a longitudinal groove in which rests the ascending process of the premaxil- 
lary and farther back is an oblique temporal ridge, extending from the olfactory notch to 
the middle of the interfrontal suture, and serving as the anterior limit of the temporalis 
muscle. 
2. PARIETAL. This is the most irregular bone of the skull, and the largest, with the 
exception of the parabasal. It possesses extensions in several directions, but it is so irreg- 
ular that the number 
Antero-Lateral of definite processes, 
Process 
Antero-laterat 
Process 
of which Wiedersheim 
enumerates five, is 
somewhat arbitrary. 
median Of these, the most 
Antero- Process) 
a median important function- 
Orbito-Sphenoid Process 
Process. = ally as well as ana- 
a PBL '' 3 : . 
& tomically, is the lon- 
= - . . 
Quad rate 3 Alerts gitudinal ridge upon 
ay Ir . 
Peer 3 bis the ventral side, the 
Y . 
: edge of which comes 
Pro-otic € Pp ty 4 : 
Precess. £ ny in contact with the 
‘ Process. 
parabasal, and which 
functionally replaces 
an orbito-sphenoid and 
serves as the side 
z Opisth oti = 
Opisthot of the brain case. 
Process ~ VENTRAL DORSAL hee 
This may be called 
Fig. 14. Two views of right parietal. > 3. Contact surfaces with other bones 
are designated by an x. the orbito-sphenoid 
process, as sugges- 
tive of its function, 
and this process together with the uncinate process on the frontals completes the U- 
shaped ridge mentioned above. This ridge is perforated by several very slanting foramina 
for the transmission of the nerves of the eye muscles, but the exact identification of these 
must be left for later investigation. The irregularly curved and very thin dorsal surface 
may be conveniently divided into a nearly flat anterior portion and a decidedly convex 
posterior portion, taking its shape from the otic capsule which it covers. From the 
anterior portion proceed three processes, an antero-median, an antero-lateral, and a quad- 
