PLATE XXIV. 



Streptelasma ampliatum. 

 Page 423. 

 Fig. 1. Posterior view of a specimen. 

 Fig. 2. View of the calyx. 

 Fig. 3. The elevation in the center of the cup of the preceding. 



Streptelasma conspicuum. 

 Page 433. 

 Fig. 4. Posterior view of the specimen showing the calyx. 



Streptelasma fossula. 

 Page 423. 

 Fig. 5. Posterior view of the specimen. 



Streptelasma crateriporme. 

 Page 424. 

 Fig. 6. Posterior side of the specimen. 

 Fig. 7. The calyx of the preceding. 



Streptelasma involutum. 

 Page 424. 

 Fig. 8. Lateral view of a specimen. 

 Fig. 9. The calyx of the same. 



Streptelasma ^equtdistans. 

 Page 424. 

 Fig. 10. Side view of the specimen. 

 Fig. 11. The form of the calyx. 



Streptelasma mammiferum. 



Page 425. 



Fig. 12. Specimen nearly entire, preserving the conical elevation in the center. 



Fig. 13. Lateral view of a broken specimen showing the interior of the cup 



and the twisted lamellae in the center. 



Streptelasma papillatum. 

 Page 425. 

 Fig. 14. Posterior view showing the calyx. 

 Fig. 15. Lateral view of another individual. 



Streptelasma coarctatum. 



Page 425. 



Figs. 16, 17. Lateral and posterior views of a specimen; the latter showing the 



interior of the calyx with the twisted lamellae. 



