arr. 16. TWO SQUALODONTS FROM MARYLAND—KELLOGG. 45 
d', Maxillae broadly overlapping frontals and not extending posteriad to 
anterior margins of temporal fossae. Rostrum broad at base, short and 
stout. Maxillary notches reduced in extent. External nasal openings 
situated more anteriorly than in Squalodon. Supraorbital process of 
frontal broad, expanded laterally, its anterior margin rounded and its 
posterior produced backward as the tapering postorbital process. Pre- 
maxillaries bounding nasals laterally, overriding frontals mesally, but 
terminating in advance of anterior margins of parietals. Parietals form 
the intertemporal region of the skull. Supraoccipital subtriangular 
in outline, equaling at base more than one-half greatest width of skull 
across squamosals. Mesorostral channel open. Occipital condyles 
large, their articular faces and necks produced beyond posterior mar- 
gins of temporal fossae (South Carolina) ......Agorophius pygmaeus 
DESCRIPTION OF A NEW SPECIES OF SQUALODON FROM THE 
CALVERT CLIFFS, MARYLAND. 
SQUALODON CALVERTENSIS, new species. 
Type.—No. 10484, Division of Vertebrate Paleontology, United 
States National Museum. This specimen consists of a nearly com- 
plete skull, including the greater portion of the rostrum; the palatal 
region is imperfect, and the jugals are missing. One periotic is pre- 
served. Four molars, three premolars, and four incisorlike teeth were 
found associated with the skull. A mandible, two dorsals, and three 
lumbar vertebrae, six isolated epiphyses of vertebrae, ten ribs and one 
ulna also belong to this specimen. 
Type locality.—The occurrence is as follows: Near latitude 38° 40’ 
end longitude 76° 32’ on the western shore of Chesapeake Bay, 
about 2 miles south of Chesapeake Beach, Calvert County, Maryland. 
Shown on Patuxent Quadrangle or Patuxent Folio No. 152, United 
States Geological Survey. 
Horizon.—The specimen was discovered and excavated by Norman 
H. Boss on July 8, 1921. It was dug from the cliffs 5 feet above the 
beach. The oyster shell stratum is not visible at this point and is 
probably well under the beach level. The specimen apparently was 
dug from Shattuck’s zone 6 of the Calvert Miocene formation of Mary- 
land. 
SKULL. 
Dorsal view.—The most obvious peculiarity of this skull (pl. 1) is 
the apparent expansion of the rostrum at the tip. Some doubt may 
exist whether this modification was a natural one or whether it was 
the result of pressure exerted by the overlying strata. The separa- 
tion of the premaxillae may have occurred during the process of 
weathering subsequent to the animal’s death and before it was cov- 
ered by the sediments which insured its future preservation. The 
imperfect state of preservation of certain exposed parts of the skull 
lends some support to the latter view. Otherwise, the long-tapering 
rostrum presents essentially the same features as other previously 
60466—23—Proc.N.M.vol.62 39 
