Page:Walcott Cambrian Geology and Paleontology II.djvu/190

124 and Polynoidæ, radiate or point from the axis of the body backward and outward along the sides. An example of a recent annelid covered with dorsal scales is furnished by Iphionella cimex De Quatref, and dorsal spines are a distinctive character on Lætmonice producta willemœsii, L. producta wyivilli, and Lætmonice aphrodites. The form, size, and surface markings of the scales and spines of Wiwaxia are well shown by the illustrations on pl. 21. In fig. 4 the slender cylindrical proximal extension of the end of the scale and also of the dorsal spines is well shown; this extension probably continued down into the sac from which the scale began its growth. The spines are probably modified scales, but they may correspond to the dorsal spines of the recent annelids referred to above. A very fine surface ornamentation consisting of minute, irregularly outlined, transversely oblong spaces also occurs on the scales. The scattered scales and spines are often very abundant. It was one of the spines that Dr. G. F. Matthew described under the name of Orthotheca corrugata. It is hoped that specimens showing the ventral surface of the animal will be found in the near future.

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.

The generic and specific characters known are given under the description of the species.

Genotype.—Pollingeria grandis, new species.

Stratigraphic range.—The stratigraphic range is somewhat greater than that of Wiwaxia corrugata, with which it is associated in some layers. The scales have been found extending up from the Phyllopod bed (page 130) through about 30 feet of shale.