PLATE XXXIII. 
LINGULELLA LENS (Matthew) (p. 512). 
Ficure 1, Ventral valve broken and embedded in limestone. University of Toronto, Canada. Type specimen, 
figured by Matthew [1901, Pl. V, fig. 8a] as Lingula ? lens. 
Ja. Ventral valve showing outline of a smaller shell than that represented by figure 1. U.S. Nat. Mus. Cat. 
No. 51767a. 
lb, 1c, and 1d. Partly exfoliated dorsal valves varying somewhat in outline and size. U.S. Nat. Mus. 
Cat. Nos. 51767b, 51767c, and 51767d, respectively. 
The specimens represented are all from Locality 10r, Upper Cambrian shales of Division C3a? of Matthew, at 
McAdam Shore, East Bay, Cape Breton, Nova Scotia. 
LINGULELLA CONCINNA Matthew (p. 486). 
(Pl. XXXIV, figs. 1, la-r.] 
Ficure 2. Ventral valve broadened by movement in the fine shale of Locality 3h, Upper Cambrian, McNeil Brook, 
Cape Breton, Nova Scotia. U.S. Nat. Mus. Cat. No. 51762s. 
2a. Ventral valve that occurs on the same hand specimen with the shell represented by figure 2. It has been 
elongated by the movement which broadened figure 2. U.S. Nat. Mus. Cat. No. 51762t. 
2b, Ventral valve associated with the shell represented by figure 2, preserving its original outline. U.S. 
Nat. Mus. Cat. No. 51762u. (See note following description of fig. 2h.) 
2¢e. Small dorsal valve associated with the specimen represented by figure 2. U.S. Nat. Mus. Cat. No. 51762v. 
2d. Dorsal valve, the type specimen, slightly broadened by compression; from Locality 307, Upper Cam- 
brian, McLeod Brook, Cape Breton, Nova Scotia. University of Toronto, Canada. Drawn from one 
of the specimens figured by Matthew [1901, Pl. V, figs. 2a—b], but closer identification is impossible. 
2e. Dorsal valve associated with the specimen represented by figure 2, slightly broadened by compression. 
U.S. Nat. Mus. Cat. No. 51762w. 
2f. Dorsal valve associated with the specimen represented by figure 2, more or less distorted by compression in 
the shale. U.S. Nat. Mus. Cat. No. 51762x. 
. Distorted dorsal valve from Locality 372, Upper Cambrian shale at Upper Leitches Creek, Cape Breton, 
Nova Scotia. U.S. Nat. Mus. Cat. No. 52449a. 
2h. Dorsal valve associated with the ventral valve represented by figures 2 and 2b. U.S. Nat. Mus. Cat. 
No. 51762y. Figures 2b and 2h preserve the original convexity and outline of the shell more 
perfectly than those compressed in the fine shales. 
Osoius (WesronrA) ELLA (Hall and Whitfield) (p. 455). 
(Pl. XLVII, figs. 1, la-p.] 
Fictres 3 and 3a. Associated dorsal valves distorted by movement in shale, one being broadened, and the other 
elongated. U.S. Nat. Mus. Cat. Nos. 51684a and 51684b, respectively. 
3b and 3c. Dorsal and ventral valves compressed and distorted in fine shale. U.S. Nat. Mus. Cat. Nos. 
51684c and 51684d, respectively. 
The figures all represent specimens from Locality 8c, Middle Cambrian shales near Ophir, Utah, and are intro- 
duced to illustrate the forms this species may often take where the fine shells have been more or less compressed and 
stretched. They should be compared with the prevailing form of the species as shown on Plate XLVII. 
LINGULELLA (LINGULEPIS) EXIGUA (Matthew) (p. 551). 
[Pl. XLIII, figs. 1, la-z.] 
Fiaure 4, Group of young shells occurring in fine, arenaceous shale, Locality 3i, Middle Cambrian on McLean Brook, 
1.5 miles west of Marion Bridge, Cape Breton, Nova Scotia, in which the adult specimens represented 
on Plate XLIII occur. U.S. Nat. Mus. Cat. No. 34761s. 
4a. Specimen in which the substance of the shell has been etched by acid so as to leave in relief the siliceous 
matter filling the fractures in the shell. Locality 10s, Middle Cambrian sandstone on McLean 
Brook, near Marion Bridge, Cape Breton, Nova Scotia. U.S. Nat. Mus. Cat. No. 52468a. The 
original specimen is 12 mm. in length. The system of fractures is very complicated within the two 
main lines of fracture which cross each other obliquely, forming rhomboidal spaces. 
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