68 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62, 
condyle; Can. op., canalis opticus; Cr. 1., lambdoidal crest; Ez. 0., exoccipital; 
Fo. c., condylar foramen; Fo. lac. med.**, foramen lacerum medium; fo. lac. post., 
foramen lacerum posterius; Fo. m., foramen magnum; Fr., frontal; F's. petr., fossa 
petrosi; Gl. f., glenoid fossa; Za., lachrymal; M.'-WM.’, first to seventh molars, 
inclusive; Mar., maxilla; Meat. aud. ert., meatus auditorius externus; Mes., meseth- 
moid; N. A., external openings of nasal passages; Na., nasal; Pa., parietal; Pa. p., 
paroccipital process; Pm.3-Pm.*, third to fifth premolars, inclusive; Pmz., pre- 
maxilla; Po. gl. p., postglenoid process; Po. p., postorbital portion of supraorbital 
process of frontal; Pr. falc., processus falciformis; Pr. p., preorbital portion of supra- 
orbital process of frontal; Prs., the posterior end of the presphenoid is exposed in this 
open suture in front of the basisphenoid; Pt., external pterygoid; So., supraoccipital; 
Sph. f., sphenoidal fissure; Sq., squamosal; Vo., vomer; X., internal openings of 
nasal passages were present at this point originally, but were not preserved in this 
skull—the region they would occupy having been filled in with plaster of Paris. 
PLATE 2. 
Type skull of Squalodon calvertensis, new species. About two-fifths natural size. 
Ventral view. 
PLATE 3. 
Type skull of Squalodon calvertensis, new species. About two-fifths natural size. 
Lateral view. The parieto-squamosal and parieto-frontal sutures indicated in this 
figure represent the relations existing between these elements on the left lateral 
wall of the cranium. 
PLATE 4. 
Type skull of Squalodon calvertensis, new species. About two-fifths natural size. 
Posterior view. 
PLATE 5. 
Type mandible of Squalodon calvertensis, new species. About seven twenty-fifths 
natural size. Fig. la, external view; Fig. 1b, superior view. 
PLATE 6. 
Fig. 1. Type mandible of Squalodon calvertensis, new species. About seven twenty- 
fifths natural size. Internal view. 
2. Right ulna of Squalodon calvertensis, new species. About twenty-one 
twentieths natural size. External view. 
PLATE 7. 
Teeth of Squalodon calvertensis, new species. About natural size. Fig. 1, posterior 
lower molar, right side; Fig. 2, second upper molar, left side; Fig. 3, second 
lower molar, right side: Fig. 4, second upper molar, right side; Fig. 5, fourth 
upper premolar, left side; Fig. 6, third lower premolar, right side; Fig. 7, 
fourth lower premolar, right side. 
PuaTeE 8. 
Four teeth and a right periotic of Squalodon calvertensis, new species. About 
natural size. Fig. 1, lower canine ?; Figs. 2-4, upper incisors ?; Fig. 5, ventro- 
internal view of periotic; Fig. 6, internal view of periotic. 
PLATE 9. 
Anterior dorsal vertebra of Squalodon calvertensis, new species. About one-half 
natural size. Fig. 1, anterior view; Fig. 2, superior view; Fig. 3, posterior 
view. 
_ & The line leading from Fo. lac. med. on plate 2 terminates at an opening which may represent the 
foramen ovale; it should have been continued inward for 3. mam. or more to a smaller foramen. 
