PLATK XXXir. 



COLEOLUS OBBNATOCINOTnM. 

 Page 188. 



V\g. 1. k fragrnient in chert, where the shell is crystallized in silica ; natural size. The Bection below shows 



the diameter of the tube, and proportional thickness of the shell. 

 Fig. 2. An enlargement from a small fragment of another individual in chei-t, whei-e the surface character 



are preserved. 

 Vig. 3. An elongate tubular foi-m in limestone, which apparently belongs to this genua and epecies. 

 Fig. 4. A fragment of similai- character with the preceding, but more curved and irregular. 



CoLEOLUS TENDIOINOTUM. 



Page 185. 



Fig. 5. A small individual which is cinished at the larger end. Owing to the position of the individual, the 



strite appear to be directly transverse. 

 Fig. 6. A larger flattened specimen, which is fractured longitudinally along the centre of the exposed surface 



The strife are oblique. Figure enlarged. 

 Fig. 7. An individual with finely striated surface, the upper end of which is partially inclosed in a striated 



fold of shale. The striae on the shale ai-e due to slipping or concretionary action. Enlai'ged. 

 Fig. 8. A small specimen in its natui-al proportions, enlai-ged two diameters, showing the slightly expanding 



cylindrical tube, with its characteristic annulations. 

 Fig. 9. A further enlargement of a portion of the specimen figure 8, showing the oblique annulations and 



fine longitudinal strise. 



Clathrocoslia eborica. 



Page 204. 

 Fig. 10. The exposed face of the specimen in shale, showing the arching septa (or laminte), with the longi- 

 tudinal lines obscurely indicated. 



Htolithes liqea. 



Page 195. 

 Fig. 11 . The venti-al surface of a specimen, showing the faintly^impressed sides with a more strongly convex 



centre. 

 Fig. 12. View of the dorsal side, showing the deeply concave margin of the aperture. 

 Fig. 13. Profile view of the same, showing the relative convexity of the two sides of the specimen. 

 Fig 14. The doi-sal surface of a sjiecimen. From the Schohai-ie gi'it. 

 Fig. 15. A transveree section of the specimen, figure 12. 

 Fig. 16. A smaller individual of the same species (?) which has been some what irregular in its mode of g^wth. 



HyOLITHES PRINCIPALIS. 

 Page 196. 

 Figs. 17-19. Three views of an imperfect specimen, showing the rapid increase in diameter, the relative 

 convexity of the opposite sides, and the ai-ching of the lip of the aperture on the convex side of 

 the shell. 

 Fig. 20. The doi-sal sui-face of a large specimen supposed to belong to this species, but showing more angu- 

 larity along the middle, and a different ratio of increase in width. 

 Fig. 21. A transverse section of the specimen, figui-e 17. 



