90 The available evidence thus indicates that the Ingenika group is in part, possibly in large part, of Lower Cambrian age. There is no further evidence to indicate whether all of the rocks mapped in the group are of the same age, or what range of age is represented. If the coral-like fossils found west of the Beveley mineral claims are of Silurian or Devonian age, as tentatively suggested by Dr. Okulitch, the rocks from which they come should not be included in the Ingenika eroup. As previously described, the Ingenika group rocks lie with angular conformity on the Tenakihi group rocks, the contact between the two groups being drawn below the stratigraphically lowest unit containing the distinctive conglomerates characteristic of the Ingenika group. The top of the group is nowhere exposed, and the overlying unmetamorphosed rocks of late Paleozoic and younger age are faulted against the Ingenika group beds. CorRELATION The Ingenika group rocks can be traced southeast from Aiken Lake map-area to the valley of Omineca River, where McConnell (1896, p. 24) correlated the conglomerate, quartzites, and slates with the Bow River series of Lower Cambrian and Precambrian age, and the limestones with the Castle Mountain group of Middle Cambrian to Cambro-Silurian (Ordovician) age. McConnell found no fossils, and based his correlation with the type area, some 450 miles to the southeast, on lithological similarity alone. The archaeocyatha in Tenakihi Range indicate a correlation with the Donald formation, the uppermost Lower Cambrian formation of the Purcell Mountains (Evans, 1933, p. 122), and the equivalent of beds in the lower part of the series of formations now considered to correspond with the Castle Mountain group of McConnell. Okulitch (1949) has summar- ized the relations between lithological equivalence and fossil correlation of the Precambrian and Cambrian rocks of that part of the Cordillera 300 miles southeast of Aiken Lake map-area, and his suggestion of an east- ward-migrating geosyncline in Late Precambrian and Cambrian time, supplied mainly by sediments from a retreating eastern shore of fairly high relief, is compatible with the meagre evidence regarding the origin of the Tenakihi and Ingenika groups. In the Cariboo Mountains, about 250 miles southeast of Aiken Lake map-area and in much the same regional geological setting, beds of quartzite and limestone contain a Lower Cambrian trilobite fauna (Lang, 1938, p. 14).1 These beds may be correlative with the Ingenika group beds, and they overlie with apparent conformity the Cariboo series, which may correspond with the Tenakihi group, and which like it is, presumably, of Precambrian age. In the Toad River-Muncho Lake area along the Alaska Highway, 130 miles due north of Aiken Lake map-area, Williams (1944) and Laudon and Chronic (1949) found a thin series of tan quartzites and sand- 1In 1953, archaeocyatha ‘similar to those found in the Ingenika group were collected from similar beds in the Cariboo Mountains by A. Sutherland-Brown of the British Columbia Department of Mines (V. J. Okulitch, personal communication, 1953).