Plate IV 
Cleiothyridina lata n. sp. 
Figures 1 a, b, o. Anterior, brachial, and side views of the type specimen, slightly imperfect. 
Section 2, locality 35. (Page 71.) 
Myalina mtssissippietma n, sp. 
Figures 2, 3, 4, 5, 6, 7. Views of separate left valves. Figure 5 is a side view showing the 
convexity of the valve; Figure 6 is a young shell showing the small anterior ear. Figure 4 is desig- 
nated as the type. Section 2, locality 22. (Page 75.) 
Allorisma albertense n. sp. 
Figures 8 a, b, c, d. Drawings and photographs of the right valve and of the anterior end of 
the type specimen. Section 2, locality 24. (Page 77.) 
Loxonema Tockymontanum n. sp. 
Figures 9 a, b. Two views of the type specimen, lacking the last whorl. Section 2, locality 25. 
Figure 10. V iew of the anterior whorl of a mature specimen. Section 2, locality 25 . (Page 81 . ) 
Conularia altemistriata n. sp. 
Figure 11 a, b. Two side views of the species, X 2f. Section 2, locality 25. (Page 84.) 
