PLATE CXVI. 
CORNULITES PROPRIUS. Hall. 
Page 19. 
Fig. 1. A single young individual attached to the shell of Strophostylus cyclostomus. The transverse an- 
nulations ai-e very conspicuous, but the longitudinal striae are scarcely developed. 
Fig. 2. A group of three individuals in the same stage of development, attached to the shell of Platyostixma 
Nlagarense. 
Fig. 3. A group of young individuals attached to a gastropod shell and exhibiting an ii'regularly circular 
arrangement in their mode of growth. 
Fig. 4. A young individual attached for its entire length to a branch of Trematopora. 
Fig. 5. A later stage of growth, in which the transverse annulations are less regular and the longitudinal 
striae distinctly visible. This tube is attached to a fragment of Lichenalia, and i-etains its in¬ 
curved apical portion. 
Fig. 6. A specimen in a similar stage of growth, also retaining the apical portion of the tube. 
Fig. 7. A somewhat crushed individual attached to the shell of RhyncTionella Stricklandi. 
Fig. 8. Two large tubes attached by their apices to a shell of Platystoina Niagarense, leaving the body 
of the tube neai-ly free. In this stage of development the annulations are obsolescent and less 
regular, and the longitudinal strise consjiicuous. The terminal portion of left tube is restoi-ed 
in the drawing. 
Fig. 9. A somewhat larger individual attached to the calyx of Eucalyptocrinus o'assHs. The attached 
portion of the tube is flattened and united by nearly its entire width to the crinoidal plates. 
The annulations are obsolete. 
Fig. 10. A very large individual, showing the characters of the fully developed form, in which the annula¬ 
tions have become very irregular and obsolescent, and the longitudinal striae correspo ndingly 
prominent. 
Fig. 11. A somewhat crushed specimen, showing very irregular growth, a strongly striated surface, and 
the repair of injuries received during the life of the animal. 
Fig. 12. Another specimen, showing similar characters. 
Fig. 13. An enlargement of the surface of the last specimen, showing the character of the longitudinal striae 
and the abrupt change at one of the concentiic ridges. 
Fig. 14. An enlarged longitudinal section of a young tube, in which the annulations are well develo^ied ; 
showing the thickness of the'vesicular wall. 
Fig. 15. A longitudinal section of a larger individual, natural size, showing the thickness of the vesicular 
wall and the annular ridges of the internal surface. 
Fig. 16. A longitudinal section of a large tube, in which the vesicular wall is quite thin, and the inner 
surface strongly annulated. 
Fig. 17. A longitudinal section of a large tube, the vesicular walls of which ai-e very thick. 
Fig. 18. An enlargement of a portion of the left wall, represented in fig. 17, showing moi’e distinctly the 
vesicular structure of the walls and the formation of a layer of vesicular tissue over the annu¬ 
lations of the internal surface. 
Fig. 19. A transverse section of a tube, natural size, showing the thickness of the walls. On the upper 
margin, and on the right hand lower mai-gin are intervals where the cellular tissue has not 
been developed. 
Fig. 20. A similar transverse section, enlarged. 
Fig. 21. A still greater enlargement from the same specimen. 
The specimens illustrated in the preceding figures 1-21 are all from the 
Niagara group. Waldron, Indiana. 
CORNULITES Clintoni. Hall. 
Page 18. 
Fig. 22. An internal cast of a tube, showing impressions of the strong annulations upon the inner surface. 
Clinton group. Near LocTtpoi't, Niagara county. 
