Page:Walcott Cambrian Geology and Paleontology II.djvu/189

NO. 5 Formation and locality.—Middle Cambrian: (35k) Burgess shale member of the Stephen formation, on the west slope of the ridge between Mount Field and Wapta Peak, one mile (1.6 km.) northeast of Burgess Pass, above Field; and (14s) about 2300 feet (701 m.) above the Lower Cambrian and 2700 feet (823 m.) below the Upper Cambrian, in the Ogygopsis zone of the Stephen formation, at the great "fossil bed" on the northwest slope of Mount Stephen, above Field on the Canadian Pacific Railway; both in British Columbia, Canada.

Body oval; covered with dorsal ribbed scales and strong, elongate spines.

One genus, Wiwaxia.

The generic and specific descriptions are united under the description of the species.

Genotype.—Wiwaxia corrugata (Matthew).

Stratigraphic range.—The stratigraphic range is limited to a band of dark siliceous shale about 4 feet in thickness forming a part of the Burgess shale member of the Stephen formation at locality (35k) near Burgess Pass, and on the slope of Mount Stephen it was found in the trilobite beds of locality (14s).

Geographic distribution.—On the slope of the ridge between Wapta Peak and Mount Field, north of Burgess Pass, and about 3800 feet above Field on the line of the Canadian Pacific Railway; also on the slope of Mount Stephen 2300 feet above Field; both in British Columbia, Canada.

Generic name derived from Wiwaxy, name of several small mountain peaks north of Lake O'Hara, British Columbia, Canada.

Orthotheca corrugata, 1899, Trans. Roy. Soc. Canada, 2d ser., Vol. 5, sec. 4. p. 42, pl. 1, fig. 3.

Orthotheca corrugata, 1908, Canadian Alpine Journal, Vol. 1, No. 2, p. 246, pl. 1, fig. 11.

This fine species is represented by a number of specimens of nearly the entire dorsal surface, which appears to have been covered by scales. The best example of what was probably the entire dorsal outline is illustrated by fig. 2, the anterior end being at the left or next to the side of the plate. The scales, as on the recent