PLATE XCIX. 300 
Prorortuis (LOPERIA) DUGALDENSIS Walcott (p. 744). 
Fieaures 5, 5’,and 5’. Top, side, and posterior views of a mold of the interior of a ventral valve, the type specimen. 
U.S. Nat. Mus. Cat. No. 52440a. 
5a. A compressed and distorted ventral valve from Locality 2u, Middle Cambrian, south side of Long Island, 
Kennebecasis Bay, St. John County, New Brunswick. U.S. Nat. Mus. Cat. No. 52446a. 
5b. Side outline of the natural mold of a ventral valve. U.S. Nat. Mus. Cat. No. 52440b. 
5b’. View looking from front margin toward the area and spondylium, as shown in a cast of a ventral valve. 
Same specimen as represented by figure 5b. 
5¢ and 5c’. Top and side views of the natural mold of a ventral valve. The outline 5c’ shows the position of 
the short spondylium just beneath the beak. U.S. Nat. Mus. Cat. No. 52440c. 
5d; 5e, 5e%; 5f, 5f”; 5g; and 5h, 5h’. Top and side views of natural molds of five dorsal valves. U.S. Nat. 
Mus. Cat. Nos. 52440d-h, respectively. 
5i. Enlargement of the outer surface obtained by making a cast from the matrix of the surface. U.S. Nat. 
Mus. Cat. No. 52440i. 
5j. Exterior of a ventral valve, drawn from impressions obtained in a natural matrix. U.S. Nat. Mus. Cat. 
No. 52440). 
The specimens represented by figs. 5, 5b-j (not 5a) are from Locality 10p, Middle Cambrian sandstones of Division 
E2b of Matthew on Dugald Brook, Indian River, Cape Breton, Nova Scotia. 
Protortuis L&VvIs Walcott (p. 741). 
Ficures 6, 6a, and 6b. Top, back, and side views of the type specimen, from Locality 79a, Upper Cambrian ‘‘St. 
Croix sandstone” 0.5 mile (0.8 km.) southeast of the county courthouse, Menomonie, Dunn 
County, Wisconsin. U.S. Nat. Mus. Cat. No. 52429a. 
