Page:Walcott Cambrian Geology and Paleontology II.djvu/302

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214

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. 57

DESCRIPTION OF PLATE 27
				PAGE
Burgessia bella Walcott (see pl. 30)				177
	Fig.	1.	(✕3.) Dorsal view of a specimen showing the internal structure through the thin carapace. st = stomach, i = intestinal canal, kd = hepatic cæca, cl = connection between hepatic cæca and alimentary canal, thl = thoracic legs, ab = abdominal region, but the segmentation is not preserved in this specimen. U. S. National Museum, Catalogue No. 57676.
		2.	(✕3.) Ventral view of the region beneath the carapace. Lettering the same as for figure 1 with the addition of a' = antennæ, lb = labrum. U. S. National Museum, Catalogue No. 57677.
		3.	(✕3.) Dorsal view of area within the cephalic shield, showing interior and appendages of the head. e = eye, a" = antennæ, 3, 4, 5 = cephalic appendages, th = base of thoracic appendage. Other lettering as in figures 1 and 2. U. S. National Museum, Catalogue No. 57678.
Waptia fieldensis Walcott				181
	Fig.	4.	(✕1.5.) Dorsal view of a specimen flattened on the shale. c = carapace, e = eye, a' = antennæ, thl = thoracic legs, cr = caudal rami. U. S. National Museum, Catalogue No. 57681.
		5.	(✕2.) Side view with carapace (c) pushed over forward so as nearly to reverse the position of the dorsal line. th = thoracic segments, thl = thoracic legs, ab = abdominal segments, cr = caudal rami, m = mandible, m' = maxillula, m" = maxilla, br = gill lobe. U. S. National Museum, Catalogue No. 57682.
Opabinia regalis Walcott (see pl. 28, fig. 1)				167
	Fig.	6.	(✕2.) Lateral view of the type specimen of the male of the species. The eyes (e) are crushed one beside the other. fp = frontal appendage, ths = trunk somites, br = gills, f = terminal lobe-like joints of thoracic legs, t = telson or terminal somite. U. S. National Museum, Catalogue No. 57683.

All of the specimens illustrated on Plate 27 are 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.