PLATE XXXyV. IPA 
LINGULELLA ATAVA (Matthew) (p. 479). 
Fiaure 5. Exterior of ventral valve from Locality 18n’, Middle Cambrian sandstones of Division E3e, Dugald Brook, 
Cape Breton, Nova Scotia. Type specimen, figured by Matthew [1899b, Pl. II, fig. la] as Leptobolus 
atavus. 
5a and 5b. Partly exfoliated ventral valves, showing area, pedicle furrow, and outline of visceral cavity. 
Locality 10p, Middle Cambrian sandstones of Division E2b, Dugald Brook, Cape Breton, Nova Scotia. 
U.S. Nat. Mus. Cat. Nos. 35293a and 35293b, respectively. 
5c. Dorsal valve associated with the specimens represented by figure 5. University of Toronto, Canada. 
Specimen figured by Matthew [1899b, PI. II, fig. 1d] as Leptobolus atavus. 
5d. Cast of interior of dorsal valve, showing outline of visceral area, position of anterolateral muscle scars, 
vascular sinuses, and area. Locality 13n’, Middle Cambrian sandy shales of Division E3e, Dugald 
Brook, Cape Breton, Nova Scotia. U.S. Nat. Mus. Cat. No. 52450a. 
5e. Dorsal valve. The specimen can not now be located. It was in the collections of the United States 
National Museum, but the locality is unknown. 
5f, 5g, and 5h. Casts of laterally compressed dorsal valves associated with the ventral valves represented by 
figures 5a and 5b. U.S. Nat. Mus. Cat. Nos. 35293c, 35293d, and 35293e, respectively. 
LINGULELLA FLUMENIS (Matthew) (p. 500). 
Fieure 6. Exterior of imperfect ventral valve. University of Toronto, Canada. 
[1903, Pl. XI, fig. 7a] as Leptobolus flumenis. 
6a. Interior of dorsal valve. University of Toronto, Canada. Specimen figured by Matthew [1903, Pl. XI, 
fig. 7b] as Leptobolus flumenis. 
6b. Cast of interior of dorsal valve. University of Toronto, Canada. 
Pl. XI, fig. 7e] as Leptobolus flumenis. 
Type specimen, figured by Matthew 
Specimen figured by Matthew [1903, 
The specimens represented are all from Locality 325a, Middle Cambrian shales of Division C2c on McNeil Brook, 
Cape Breton, Nova Scotia. 
LINGULELLA TORRENTIS (Matthew) (p. 535). 
Figure 7. Ventral valve from Locality 344f, Middle Cambrian shales of Matthew’s Coldbrook group, Dugald Brook, Cape 
Breton, Nova Scotia. University of Toronto, Canada. Type specimen, figured by Matthew [1903, 
Pl. VI, fig. 1] as Leptobolus torrentis. 
LINGULELLA ATAVA INSULZ (Matthew) (p. 480). 
Fieures 8 and 8a. Ventral and dorsal valves from Locality 307d, Middle Cambrian sandy limestone ot Division E2a?, 
at Youngs Point near George River Station, Cape Breton, Nova Scotia. University of Toronto, Canada. 
Specimens figured by Matthew [1903, Pl. VI, figs. 4a and 4b] as Leptobolus atavus insule. Figure 8 
represents the type specimen. 
LINGULELLA oRA (Walcott) (p. 522). 
Figure 9. Exterior of a broken ventral valve, the type specimen, from Locality 9p, Upper Cambrian limestone, 15 
, miles northwest of Fort Sill, Comanche County, Oklahoma. U.S. Nat. Mus. Cat. No. 51794a. 
9a and 9a’. Top and side views of a partly exfoliated ventral valve which illustrates the thickness of the 
shell, from Locality 9q, Upper Cambrian limestone, 15 miles northwest of Fort Sill, Comanche County, 
Oklahoma. U.S. Nat. Mus. Cat. No. 51795a. 
9b and 9b’. Top and side views of a ventral valve associated with the shell represented in figure 9, showing 
the outer surface of one of the inner layers of the shell. U.S. Nat. Mus. Cat. No. 51794b. 
9c and 9c’. Top and side views of an elongate dorsal valve associated with the shell represented in figure $. 
U.S. Nat. Mus. Cat. No. 51794c. é 
9d. Short broad form of dorsal valve associated with the shell represented in figure 9. U.S. Nat. Mus. Cat. 
No. 51794d. 
