PLATE LVIII. 193 
ACROTHELE BELLULA Walcott—Continued. 
Figure 5c. Enlargement of the cast of the interior of a ventral valve associated with the shell represented by figure 5 
U.S. Nat. Mus. Cat. No. 26436d. Copied from Walcott [1897b, Pl. LX, fie. 4b]. In this figure the 
line indicating the cardinal scar is extended a little too far. It should have stopped before reaching 
the depression. 
5d. Cast of the posterior portion of the interior of a ventral valve associated with the shell represented by 
figure 5. U.S. Nat. Mus. Cat. No. 26436e. In this figure the line indic ating the cardinal scar is 
extended a little too far. It should have stopped before reaching the depression. 
5e. Cast of the interior of a small ventral valve associated with the shell represented by figure 5, showing 
vascular sinuses. U.S. Nat. Mus. Cat. No. 26436f. 
5f. Interior of a dorsal valve drawn from a cast of the specimen represented by figure 5g, showi ing the area, 
median septum, and diverging vascular sinuses. U.S. Nat. Mus. Cat. No. 26436g. nother specimen 
(Cat. No. 26436h) was used in restoring certain portions of this figure and of figure 5g. Copied from 
Walcott [1897b, Pl. LX, fig. 4c]. 
. Natural cast of the interior of a dorsal valve from Locality 90x, Middle Cambrian siliceous nodules, Coosa 
Valley, Cherokee County, Alabama. A cast of this specimen is represented by figure 5f. U.S. Nat. 
Mus. Cat. No. 264362. Copied from Walcott [1897b, Pl. LX, fig. 4d]. 
5h. Cast in shale of the interior of a dorsal valve from Locality 94x, Middle Cambrian shales near Givens Mill, 
Cowan Creek, Cherokee County, Alabama. The cardinal muscle scar is drawn too far away aon 
the median line. It should be about the length of the scar from the median line. U.S. Nat. Mus. 
_ (Cat. No. 56602b. Copied from Walcott [1897b, Pl. LX, fig. 4e]. 
or 
isi) 
ACROTHELE BERGERONI Walcott (p. 638). 
Ficures 6 and 6a. Exteriors of compressed and slightly distorted ventral valves. U.S. Nat. Mus. Cat. Nos. 51975b 
and 51975c, respectively. 
6b. Cast of the interior of a compressed and distorted ventral valve. U.S. Nat. Mus. ear No. 51975d. 
6c. Cast of the interior of a dorsal valve, the type specimen, flattened in the shale. U.S. Nat. Mus. Cat. 
No. 51975a. Copied from Walcott (1908d, Pl. VIII, fig. 11]. 
The specimens represented are all from Locality 342, Middle Cambrian shales in Montagne Noire, Coulouma, 
Hérault, France. 
62667°—vot 51, pr 2—12-_13 
