4. Sibbaldius sulphureus.

Sibbaldius sulphureus, Cope, Proc. Acad. Nat. Sci. Philad. 1869, pp. 10, 19, f. 11.

Sulphur-bottom of the Whalers on the North-west Coast.

Dorsal fin very far back.

Inhab. North Pacific, north-west coast of America, California.

5. Sibbaldius tectirostris.

Sibbaldius tectirostris, Cope, Proc. Acad. Nat. Sci. Philad. 1869, p. 7.

Inhab. North Pacific. Skeleton, Mus. Philad.

6. Sibbaldius tuberosus.