arr. 16, TWO SQUALODONTS FROM MARYLAND—KELLOGG. 63 
REMARKS ON AN UNDETERMINED SQUALODONT OF LARGE SIZE 
FROM THE CALVERT CLIFFS, MARYLAND. 
SQUALODON, species indeterminate. 
In the course of several years desultory collecting along the Calvert 
Cliffs a number of interesting cetaceans have been found. The late 
F. W. True instigated most of the collecting and encouraged William 
Palmer and David B. Mackey to make trips along the western shore of 
Chesapeake Bay. No systematic search was ever made for cetacean 
remains, but, nevertheless, in this way a miscellaneous collection of 
fossil cetaceans was built up. A number of skulls in a fair state of 
preservation were thus obtained, and, in addition to these, large 
numbers of unassociated vertebrae and teeth. In sorting over this 
material a number of fragments that pertain to at least two types of 
squalodonts were found. The smaller one of these is apparently the 
same as the species described in the present paper. The other 
represents a larger form which may possibly belong to a previously 
described squalodont, and in want of more complete material the 
writer has deferred naming the specimen. In view of the scarc- 
ity of squalodonts in North American Tertiary deposits it seems 
advisable to describe and figure some of the fragments and teeth 
which have been found. It has been known for some time that a 
large squalodont existed during the Calvert Miocene, but until re- 
cently all that was known concerning it consisted of a few broken 
teeth. In 1908 a double-rooted molar tooth of large size, but lack- 
ing most of the crown, was found adhering to a fragment of the 
maxilla by Mr. Mackey. This tooth and the other fragments herein- 
after described were acquired by purchase from Mrs. W. Palmer. 
Specimen, No. 10694, Division of Vertebrate Palaeontology, United 
States National Museum.—The material consists of one molar and a 
fragment of a maxilla. 
Occurrence.—One mile south of Chesapeake Beach, Calvert County, 
Maryland, near latitude 38° 40’ and longitude 76° 32’; shown on 
Patuxent Quadrangle or Patuxent Folio, No. 152, United States 
Geological Survey. 
Horizon.—This specimen was collected by David B. Mackey on 
July 4, 1908. It was found in the water in freshly fallen beach talus 
débris which, apparently, was derived from Shattuck’s zone 10 of the 
Calvert Miocene formation of Maryland. 
This large two-rooted molar is characterized by swollen roots which 
have a thick outer layer of cementum that flakes off when subjected 
to erosion. This layer is thickest near the tips of the roots and 
becomes thinner near the enamel crown. The dentine of the ante- 
rior root is exposed on the external side(pl. 17, fig. 16); it is dark 
brown in color. The posterior root was accidently broken and the 
. 
