66 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
groove which presumably receives the anterior extension of the 
vomer. Above this groove the surface slopes obliquely upward and 
the roughened surface of this face indicates the line of contact with 
the premaxillae. 
MEASUREMENTS FOR THE FRAGMENT OF MAXILLA, 
mm. 
Length of fragment of maxilla........... Ba) Bie pia Ae a eo) 6 ee 
Breadth of fragment of maxilla at iauiterior ieade. a SORE EB 
Breadth of fragment of maxilla at posterior endl EBLE e Re SEE SRE ary MG 
Depth of;fragment of maxilla\at;posterior end 4. -).se8./4- -\- ts aage GALE ey eT 
Antero-posterior,diameter,of first alveolus «ja... i022 3-8 20- gaten So) -ecbpec aelee, 
Transverse diameter of first alveolus.......- 2 yates aes 
Antero-posterior diameter of septum Between first and Retend aly pies. Ba Saf Sy 
Alveolae for seven teeth, four of which were two-rooted on three 
one-rooted, are present in the fragment of the left mandible (pl. 19, 
fig. 1a). The roughened internal surface of the ramus indicates a 
very long symphysis which terminated proximally near the alveolus 
for the third two-rooted tooth. An examination of the alveolae 
shows that the first and second alveolae contained single-rooted teeth, 
while the third at the time of discovery possessed a crownless tooth. 
This premolar was two-rooted, but the roots, with the exception of 
the tips, were joined throughout their length by a thin isthmus. 
Impressions made by maxillary teeth are to be observed between the 
alveolae for the posterior premolars. In the alveolae for the first 
and second two-rooted teeth, the septa which fit between the roots 
begin at least 7 mm. below the level of the superior face of the ramus, 
while those in the posterior alveolae extend the full length. On the 
external face of the mandible there are six foramina opening into the 
channels that lead anteriorly (pl. 19, fig. 1b). The more anterior 
foramina are nearer the inferior margin, while the posterior ones 
approximate the superior margin. 
MEASUREMENTS FOR THE FRAGMENT OF MANDIBLE. 
mm. 
Length of tracment of-mandiblest 2). 2204 Fal AO ee ee 367 
Vertical’ depth of proximal end of fragmento: u20. 2! 00 Pe ee os. oy BB 
Vertical depth, of-distal end, oi frasment 24.52... 2) cet 3 et bee bees be be La) pA 
Vientiesl depthioftraement near center io. 562 9 paren b ane pe ee ol arae 50 
Length. ob periect. septumeg::'4 2) acc Solan le ogee hte Seek sctobieae oe jclstc do Ge 22 
The squamosal is not complete but what is preserved exhibits some 
unusual features. In its general form, the squamosal resembles other 
previously described squalodonts; the massive zygomatic process 
and the relatively small glenoid fossa are suggestive of Squalodon 
bariensis. It differs, however, in many respects from that species. 
The zygomatic process is stout, tapering anteriorly as seen from the 
dorsal view, but rather deep dorso-ventrally. The superior margin 
does not rise abruptly above the exoccipital and presents an irregular 
outline. The postglenoid process is a strong ventrally projected plate 
