Page:Proceedings of the United States National Museum, Volume 76.djvu/143

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art. 9
new cambrian crustacea—resser
15

DESCRIPTION OF PLATES[1]

Plate 1 Page
Tuzoia retifera Walcott 7
Fig. 1. Left valve retaining the three large rear spines. In this specimen the keel was pressed down toward the lower margin, giving it a more curved shape and a more ventral position than it had in a perpendicular view of the undistorted shell and thereby the reticulations have been almost obliterated in the crushed portions and nearly effaced in places beyond this area. A specimen of the abundant gastropod, Scenella varians, projects through the shell near its lower margin. Plesiotype, Cat. No. 80484, U.S.N.M.
2. A new photograph of the original holotype figured by Walcott. In this specimen the larger marginal spines are apparently broken off. The keel is pressed almost vertically downward, thereby causing but little distortion on any part of the shell except near the front end where the reticulations show crowding. An examination of the margin indicates that both valves are present. Holotype, Cat. No. 57720, U.S.N.M.
Middle Cambrian, Burgess shale; (loc. 35k) near Field, British Columbia.
Plate 2
Tuzoia burgessensis, new species 8
Fig. 1. A well preserved specimen with the left valve uppermost. In the flattening the keel was crushed down directly to the rear. Note the three strong marginal spines and the rather regular smaller spines along the remainder of the outer margin; also the absence of intermediate spines. Several of the blunt spines along the dorsal line can be seen. Holotype, Cat. No. 80477, U.S.N.M.
Middle Cambrian, Burgess shale; (loc. 35k) near Field, British Columbia.
Tuzoia canadensis, new species 8
2. Cast of exterior of rear portion of left valve, showing the four large posterior spines. Some of the smaller more regular spines are visible forward along the lower margin. Paratype, Cat. No. 80478, U.S.N.M.
3. Major portion of right valve. Several intermediate marginal spines are visible anterior to the fourth large posterior spine. Holotype, Cat. No. 80478, U.S.N.M.
Middle Cambrian, Burgess shale; (loc. 35k) near Field, British Columbia.
Anomalocaris cranbrookensis, new species 12
4. Usual lateral view of this animal. Twelve or thriteen segments anterior to the bifiurcated caudal division. Somites and appendages may not be quite correctly outlined as specimen is little distinct from matrix. Holotype, Cat. No. 80479, U.S.N.M.
Lower Cambrian, Eager formation; (loc. 67g) near Cranbrook, British Columbia.
Roddyia typa, new species 14
5. Dorsal view of cephalic shield (✕2). Holotype, Cat. No. 80480, U.S.N.M.
Lower Cambrian, Kinzers formation; (loc. 12x) near Rohrerstown, Pennsylvania.

  1. All figures are natural size unless otherwise indicated.