PLATE ZVII. 

 Oncocbras okcas, Hall. 



Page 410. 



Fig. 1. Dorsal view of a large specimen. 

 " 2. Lateral view of the same. The figures are reduced to two-thirds the natural size. 



ClRTOCERAS DARDANUS, HaLL. 

 Page 406. 



Fig. 3. Lateral view of a specimen which preserves a part of the outer chamber and a small por- 

 tion of the shell. 

 " 4. Lateral view of an individual where the septa are not curved upward on the dorsal margin. 

 " 5. Transverse section of the specimen fig. 4. 



Cyrtoobras hbrculbs, Wijsuh. and Mar. 



Page 409. 



Fig. 6. Lateral view of a large specimen which preserves a portion of the outer chamber, and 

 also some of the surface striae near the lower end. 

 " 7. Transverse section, showing the form of the shell. The two figures are reduced one- 

 third in size. 



