For purposes of comparison, such measurements are here given as can be obtained from the skull; likewise the corresponding measurements of a specimen from Sable Island, No. 199528 of the U. S. National Museum, and of another, No. 22014 of the National Museum, brought from Ungava Bay. Unfortunately, the basilar length of the fossil can not be determined, nor the width of the mastoids. _Measurements of skulls of walruses, in millimeters._ ┌─────────────────────────────────────────────┬───────┬───────┬───────┐ │ │ Kitty │ Sable │Ungava │ │ │ Hawk. │Island.│ Bay. │ ├─────────────────────────────────────────────┼───────┼───────┼───────┤ │From front of premaxillæ to rear of vomer │ 183│ 167│ 205│ │From front of tusk to optic foramen │ 188│ 177│ 195│ │From oral border of premaxilla to upper │ │ │ │ │ border of nasal opening │ 110│ 96│ 100│ │Greatest width across maxillæ │ 160│ 136│ 177│ │Least width at front of orbits │ 105│ 106│ 146│ │Least width at temporal fossæ │ 75│ 62│ 70│ │Width between the sockets for tusks │ 75│ 75│ 85│ │Length of row of teeth │ 82│ 60│ 83│ │Space between incisors │ 40│ 36│ 32│ │Space between last molars │ 62│ 60│ 53│ │Long diameter of tusk at base │ 34│ 26│ 38│ └─────────────────────────────────────────────┴───────┴───────┴───────┘ The nasal bones of the fossil are so thoroughly consolidated with each other and with the adjoining bones that their dimensions can not be determined. There is no reason, however, for supposing that the length was greater than 70 mm. The grinding teeth of the fossil do not show the larger size that we might expect from Rhoads’s determinations and from comparison with Leidy’s illustrations. The second socket was almost exactly the diameter of the same socket in the Sable Island specimen measured. The third socket is larger than that of the skull from Sable Island. The sockets for the first molars are very small and shallow; the socket for the left incisor is still smaller, while that for the right incisor is wholly effaced. The diameter of the socket for the second molar is much shorter than that of the corresponding socket in the Ungava Bay specimen. In the latter, the left incisor is present and large, but the other is missing and the socket is nearly filled up. It is evident that the teeth are extremely variable in both size and the number present.