Page:Walcott Cambrian Geology and Paleontology II.djvu/326

DESCRIPTION OF PLATE 33
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Carnarvonia venosa Walcott				189
	Fig.	1.	(Natural size.) Dorsal view of the two valves of the carapace flattened on the surface of the shale. The adductor muscle scar (adm) shows through the test, and the fine venation extending from the head portion backward is beautifully shown. U. S. National Museum, Catalogue No. 57719.

The specimen illustrated by fig. 1 is from locality $\left({\tfrac {35k}{10}}\right)$ Middle Cambrian: Burgess shale member of the Stephen formation (about 75 feet above the phyllopod bed near the base of the shale), on the west slope of the ridge between Mount Field and Wapta Peak, one mile (1.6 km.) northeast of Burgess Pass, above Field, British Columbia.

Tuzoia retifera Walcott				187
	Fig.	2.	(Natural size.) View of flattened right valve showing reticulate surface markings. U. S. National Museum, Catalogue No. 57720.

The specimen illustrated by fig. 2 is from locality (35k) Middle Cambrian: 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, British Columbia.