3-4. Barnegat City, New Jersey. The two large teeth.
5. The same. One of the rudimentary teeth.
6. Topotype of Z. grebnitzkii. Cat. No. 22069, U.S.N.M. Bering Island. Left tooth. Outer surface.
7. The same. Right tooth. Inner surface.
8. Type of Z. grebnitzkii Stejneger. Cat. No. 20993, U.S.N.M. Bering Island. Left tooth. Inner surface.
9. The same. Right tooth. Outer surface.
10. Newport, Rhode Island. Cat. No. 49599, U.S.N.M. Left tooth. Inner surface.
11. The same. Right tooth. Outer surface.