PLATE XXXIX. 133 
LINGULELLA QUADRILATERALIS (Walcott) (p. 528). 
Figure 6. Ventral valve with outer layer of shell exfoliated, the type specimen, from Locality 91, Middle Cambrian 
shales at Cedar Bluff, Cherokee County, Alabama. U.S. Nat. Mus. Cat. No. 51777a. 
6a. Dorsal valve and side outline of united valves, associated with the specimen represented by figure 6. 
U.S. Nat. Mus. Cat. No. 51777b. 
OBOLUS CHINENSIS (Walcott) (p. 387). 
Figure 7. Partly exfoliated ventral valve, the type specimen. U.S. Nat. Mus. Cat. No. 52532a. 
7a. Interior of a ventral valve. U.S. Nat. Mus. Cat. No. 52532b. Another specimen (Cat. No. 52532c) was 
used to restore certain parts of this drawing. 
7b. Exfoliated dorsal valve, showing visceral area. U.S. Nat. Mus. Cat. No. 52532d. 
The specimens represented are all from Locality C62, Middle Cambrian limestones 2.5 miles south of Yenchuang, 
Sintai district, Shantung, China. 
LINGULELLA DAMESI (Walcott) (p. 489).4 
Fiaure 8. Top and side view of a partly exfoliated ventral valve, showing outline of posterior portion of visceral 
area and position of the main vascular sinuses. U.S. Nat. Mus. Cat. No. 52529a. 
8a. Partly exfoliated ventral valve, the type specimen. U.S. Nat. Mus. Cat. No. 52529b. 
8b. Exterior of a ventral? valve. U.S. Nat. Mus. Cat. No. 52529c. 
8c. Partly exfoliated dorsal valve. U.S. Nat. Mus. Cat. No. 52529d. 
The specimens represented are all from Locality €10, Middle Cambrian limestone about 3 miles southwest of 
Yenchuang, Sintai district, Shantung, China. 
LINGULELLA (LINGULEPIS) EROS (Walcott) (p. 551). 
Figures 9 and 9a. Ventral and dorsal valves restored in outline from other specimens. Locality €7, Middle Cambrian 
limestone 2.2 miles southwest of Yenchuang, Sintai district, Shantung, China. U.S. Nat. Mus. 
Cat. Nos. 52527a and 52527b, respectively. Figure 9 represents the type specimen. 
OxBoLus (WESTONIA) BLACKWELDERI Walcott (p. 453). 
Figure 10. An elongate ventral valve, the type specimen, with posterior portion broken away, from Locality C6, 
Middle Cambrian shaly limestone 2.5 miles southwest of Yenchuang, Sintai district, Shantung, 
China. U.S. Nat. Mus. Cat. No. 52540a. 
10a. Short form of ventral valve associated with the shell represented by figure 10. U.S. Nat. Mus. Cat. No. 
52540b. ; 
10b. Exterior of a dorsal valve from Locality C2, Middle Cambrian limestone 2 miles south of Yenchuang, 
Sintai district, Shantung, China. U.S. Nat. Mus. Cat. No. 52541a. 
10c. Enlargement of surface of a shell associated with the ventral valve represented by figure 10. U.S. Nat. 
Mus. Cat. No. 52540c. 
LINGULELLA HEBERT! Barrois (p. 505). 
11. Exterior of ventral valve. 
lla. Exterior of dorsal valve. 
11b. Cast of interior of ventral valve, the type specimen. 
lic. Enlargement of the outer surface. 
Figures 11, lla-c are copied from Barrois [1882, Pl. IV, figs. 3a-d, respectively]. The specimens represented 
are all from Locality 350a, Ordovician sandstone at Cape Vidio, Province of Oviedo, Spain. 
a Now referred to Obolus ; see p. 489. 
