PLATE LXXIV. 
Fig. 1. Development of a septum of Goxiatites bjcostatus, Hall. From the specimen fig. 8 on plate'72. 
Fig. 2. Development of a septum of G. uniangularis, Conrad. From the specimen fig. 14 on plate 71. 
Fig. 3. Development of a septum of G. disgoideus, Hail. From a young individual, repre-sauteduin .‘plate 
71, fig. 4. 
Fig-. 4. Development of a septum of an adult specimen of G. discoideus, Hall. Plate 71, fig. 13. 
Fig. 5. Development of a septum of G. unilobatus, Hall. Plate 71, fig. 15. 
Fig. 6. Development of a septum of G. Chemungbnsis, Vanuxem. Plate 69, fig. 9. 
Fig. 7. Development of a septum of G. Lyoni, Meek and Worthen. Plate 73, fig. 10. 
Fig. 8. Development of a septum of G. simulator, Hall. Plate 69, fig. 1. 
Fig. 9. Development of a septum of G. Oweni, Hall. Plate 73, fig. 3. 
Fig. 10. Development of a septum of G. Oweni, var. parallela, Hall. Plate 73, fig. 1. 
Fig. 11. Development of the left side of a septum of G. sixuosus, Hall. Plate 70, fig. 15. 
Fig. 12. Development of the right side of a septum of G. Ixion, Hall. Plate 73, fig, 13. 
Fig. 13. Development of a septum of G. peracutus, Hall. Plate 69, fig. 8. 
Fig. 14. Development of a septum of G. Mithrax, Hall. Plate 69, fig. 7. 
Fig. 15. Development of a septum of G. Patersoxi, Hall. Plate 72, fig. 3. 
