PLATE II. wl 
MicroMITRA ALABAMAENSIS (Walcott) (p. 337). 
Figure 5. Apical view of the type specimen, a compressed ventral valve, from Locality 121, Middle Cambrian Rogers- 
ville shale, 4 miles northeast of Rogersville, Tennessee. U.S. Nat. Mus. Cat. No. 51416a. Speci- 
men figured by Walcott [1897b, Pl. LIX, fig. 5] as [phidea alabamaensis. 
5a. Dorsal valve from Locality 94a, Middle Cambrian Conasauga shale, Coosa Valley, Cherokee County, 
Alabama. U.S. Nat. Mus. Cat. No. 56888a. Specimen figured by Walcott [1897b, Pl. LIX, fig. 5a] 
as Iphidea alabamaensis. ‘ 
5b. Ventral valve having a slight median depression, from Locality 14a, Middle Cambrian Rogersville shale, 
4 miles north-northeast of Knoxville, Knox County, Tennessee. U.S. Nat. Mus. Cat. No. 51418a. 
5c. Outer surface of shell from Locality 94, Middle Cambrian Conasauga shale, Cowan Creek section, Cherokee 
County, Alabama, enlarged to show the tendency to form crenulations in the strie. U.S. Nat. Mus. 
Cat. No. 26432a. This bit of surface was figured by Walcott [1897b, Pl. LIX, fig. 5b] as part of the 
surface of figure 5, magnified; it is, however, taken from another specimen. 
Micromitra (PATERINA) LOGANI (Walcott) (p. 350). 
Ficures 6, 6a, and 6b. Apical, side, and posterior views of the type specimen, from Locality 2n, Lower Cambrian 
pebbles in conglomerate at Trois Pistoles, on the St. Lawrence, Province of Quebec, Canada. Coll. 
Geol. Survey Canada. Specimen figured by Walcott [1897b, Pl. LIX, figs. 2, 2a—-b] as Iphidea logani. 
In the Canadian Survey collections it was labeled as the type of ‘Iphidea bella Billings.”’ (See 
pp. 345 and 350 and figs. 1 and 1c of this plate.) 
Micromirra (PATERINA) SUPERBA (Walcott) (p. 355). 
[Text figs. 27A-B, p. 355.] 
Figures 7, 7a, and 7b. Apical, side, and posterior views of the type specimen, a ventral valve, from Locality 73a, 
Middle Cambrian sandy ‘‘Tonto” shale, Chuar Valley, Grand Canyon of the Colorado, Arizona. 
U.S. Nat. Mus. Cat. No. 264292. Specimen figured by Walcott [1897b, Pl. LIX, figs. la—c] as [phidea 
superba. : 
7c. Specimen of the dorsal valve associated with the specimen represented by figure 7. U.S. Nat. Mus. 
Cat. No. 26429b. Specimen figured by Walcott [1897b, Pl. LIX, fig. 1] as Iphidea swperba. 
7d. Nearly perfect dorsal valve from Locality 74, Middle Cambrian sandy ‘‘Tonto” shale at head of Nunko- 
weap Valley, Grand Canyon of the Colorado, Arizona. U.S. Nat. Mus. Cat. No. 51487a. ; 
Ze. Posterior view of ventral valve, from Locality 8j, Middle Cambrian shale, near Gordon Mountain, 
Ovando quadrangle, Montana, showing pseudodeltidium. U.S. Nat. Mus. Cat. No. 51488a. 
7f. A crushed and broken ventral valve, associated with the valve represented by figure 7e, showing pseudo- 
deltidium. U.S. Nat. Mus. Cat. No. 51488b. 
MicroMItrA (PATERINA) LABRADORICA UTAHENSIS (Walcott) (p. 349). 
[Text fig. 24, p. 350.] ; 
Ficures § and 8’. Summit and side views of the type specimen, a ventral valve laterally compressed. U.S. Nat. 
Mus. Cat. No. 51431a. 
8a. Posterior half of a ventral valve somewhat distorted by compression. U.S. Nat. Mus. Cat. No. 51431b. 
The specimens represented are both from Locality 34, Middle Cambrian, Oquirrh Range, near Ophir, Utah. 
WIMANELLA SHELBYENSIS Walcott (p. 747). 
Figure 9. Type specimen, the ventral valve, flattened in the shale. Copied from Walcott [1908d, Pl. X, fig. 3]. 
9a. Interior of a flattened dorsal valve. 
The specimens represented are both from Locality 17b, Lower Cambrian Rome (‘‘Montevallo”’) formation, 4 miles 
south of Helena, Shelby County, Alabama. U.S. Nat. Mus. Cat. Nos. 52272a and 52272b, respectively. 
MicromMitra (PATERINA) WILLIARDI Walcott (p. 358). 
[Text figs. 30A-E, p. 358.] 
Ficures 9b and 9c. Side outlines of ventral valves. Drawn from casts taken in a natural mold from Locality 17b, 
Lower Cambrian Rome (‘‘Montevallo”) formation, 4 miles south of Helena, Shelby County, Alabama. 
U.S. Nat. Mus. Cat. Nos. 5148la and 51481b, respectively. 
Micromitra Nisus (Walcott) (p. 338). 
Ficure 10. Exterior of type specimen, ventral valve, from Locality 2r, Lower Cambrian, 2 miles west of Bic, Province 
of Quebec, Canada, showing radiating ridges. U.S. Nat. Mus. Cat. No. 51440a. 
Micromitra (PATERINA) LABRADORICA ORIENTALIS (Walcott) (p. 348). 
Figure 11. Exterior of type specimen, dorsal valve, from Locality C9, Middle Cambrian limestone, Kiulung group, 
3 miles southwest of Yenchuang, Sintai district, Shantung, China. U.S. Nat. Mus. Cat. No. 52516a. 
