410 DESCRIPTIONS OF NEW SPECIES OF FOSSILS, 



Plate VI. 



Illustrations of the Septa in Baculites Ovalits, B. Compressus, and B. Grandis. 



Fig. 1. Baculites ovatus, a fragment of an extremely young individual. 

 " 1, a. Plan of a septum in the smaller extremity of fig. 1. 

 " 1, b. A septum at the larger extremity of the same. 



Fig. 2. A larger individual of the same species. 

 " 2, a. Plan of a septum in fig. 2. 



Figs. 3, 4, and 5, are young individuals of larger growth than the preceding, and of which figs. 3, a, 4, a, 

 and 5, a, respectively show plans of the septa. 



Fig. 6. Plan of septum in an adult individual of Baculites ovatus. 



Fig. 7. Superior lateral lobe of Baculites ovatus, for comparison with corresponding parts of B. compressus, 

 fig. 9, and B. grandis, fig. 10. 



Fig. 8. Plan of septum in a full-grown individual of Baculites compressus. 



Fig. 9. Superior lateral lobe of B. compressus. 



Fig. 10. Superior lateral lobe of B. grandis. 



Plate VII. 



Fig. 1. Baculites grandis, a fragment of the septate portion of the shell. 



Fig. 2. Transverse section of jB. grandis. The inner figure is a section of the smaller extremity of fig. 1. 

 The second figure is of the smaller extremity of PI. VIIL, fig. 1, measured in the depressions 

 between the undulating ridges; and the outer figure is the measurement over the ridges which 

 give a different outline to the section. 



Fig. 3 and 4. Tracks of Planarian worms .' 



Plate VIII. 



Fig. 1. Baculites gra7idis ; fragment of the outer chamber, showing the transverse undulating ridges which 

 characterize this species externally. 



Fig. 2. Plan of a septum of B. grandis. 



