Page:Walcott Cambrian Geology and Paleontology II.djvu/298

DESCRIPTION OF PLATE 26

Legend:
c = carapace.	m=third appendage=mandible.
x=posterior spines or lobes of carapace.	m'=fourth appendage=maxillula.
e=eye.	m"=fifth appendage=maxilla.
lb=labrum.	i=intestine or alimentary canal.
th=thorax.	thi=thoracic legs [endopodites].
ab=abdomen.	l=setiferous jointed exopodite.
a'=antennule ?.	br=branchial lobes or gills [epipodites].
a"=antennæ.

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Marrella splendens Walcott (see pl. 25)				193
	Fig.	1.	(✕3.) Dorsal view of a specimen showing the carapace with its great posterior spines or lobes and the large antennules?. U. S. National Museum, Catalogue No. 57670.
		2.	(✕3.) Ventral view of a crushed specimen showing the labrum (hypostoma) nearly in its normal position. U. S. National Museum, Catalogue No. 57671.
		3.	(✕3.) Dorsal view of a specimen showing intestinal canal, feather-like maxillula (m), and the long joints of the setiferous exopodites. U. S. National Museum, Catalogue No. 57672.
		4.	(✕4.) Ventral view of a specimen showing the large gill lobes (br) (epipodites). U. S. National Museum, Catalogue No. 57673.
		5.	(✕3.) Dorsal view of a specimen that illustrates the relative position of the antennæ, the mandible, maxillula, and maxilla. U. S. National Museum, Catalogue No. 57674.
		6.	(✕4.) Ventral view of a specimen showing the thoracic legs (thl, endopodites) and the setiferous legs (l, exopodite). U. S. National Museum, Catalogue No. 57675.

All of the specimens illustrated on Plate 26 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.