To make clear to my readers the extraordinary difference of temperature between the sea of Palæozoic times and that now encircling the North Pole, I cannot do better than quote a few lines from Mr. Etheridge's exhaustive report on the Palæontological collections of the Expedition:—
"These undoubted reef-forming corals of the Silurian epoch were just as much inhabitants of warm water in southern latitudes at that period as are the Sclerodermata of to-day in the Indo-Pacific and Atlantic Oceans ; and as we know of no compound coral that will exist at a lower temperature than 68° F., and as the surface-waters under the equator in the Pacific have a temperature of 85° F., and in the Atlantic 83°, it seems clear that the range from 68° to 85° F. is best adapted to and not too high for the growth of the reef-making species. We may fairly assume that the temperature of the Polar waters during Palæozoic times was as high as that of the Indo-Pacific and Atlantic now, where coral-reefs abound. We are not justified in supposing that the laws regulating oceanic life were very different then from those now existing (in the same groups) under the equator or between the tropics. These corals were forms of life which must have been tropical in habits and requirements."*
At Cape Hilgard we had twenty- four hours on shore, and as the Silurian rocks of that locality are especially rich in fossils I made a very interesting collection. Birds were not numerous; during the day I observed only one Glaucous Gull and three Turnstones; one of these was shot, and found to have its stomach filled with the seeds of Draba alpina. Others of our party killed six Ptarmigan, Lagopus rupestris.
On the 16th August the ships were firmly beset close to Cape Hayes. Landing with Captain Nares and Markham, we came across the fresh footprints of a bear on the ice-foot. Vegetation was very scanty; the yellow puppy, arctic willow, with two or three species of saxifrage were all the plants we observed. A butterfly, Argynnis, was captured. It is difficult to imagine how Lepidoptera can exist in a climate which during the months of June, July and August has a mean temperature of less than three degrees above freezing and an annual mean of four degrees below zero, with falls of snow during the warmest months of the year. About a mile south of Cape Hayes a pair of Ivory Gulls were nesting in the precipitous limestone cliff. We were attracted to the spot by their shrill cries, and the movements of one of the pair
Quarterly Journal Geol. Soc, 1878, p. 57 8.
