COSMAEIUU. 129 



Apex of sendee! 1 with a slight notch. 



20. C. Trafalgaricum. 

 ft Isthmus broader ; vertical view elliptic. 



21. C. melanosporum. 



** Semicells elliptical or elliptic-oblong in outline ; sinus open. 



22. C. aspherosporum. 



23. C. inconspicuum . 



24. C. bioculatum. 



25. C. tenue. 



26. C. tinctum. 



27. C.flavum. 



28. C. contractual. 



29. C. siibcontractum. 



30. C. subaversum. 

 Semicells narrowly elliptical or elliptic-oblong, depressed. 



f Cells with a granule on each side of the sinus. 



31. C. tetraclwndrum. 

 ft Cells destitute of granules. 



32. C. depressum. 



33. C. subquadrans. 



SECTION C. Semicells distinctly pyramidate or subpyraniidate 

 in outline, usually truncate. 



* Margin of sernicells entire, not crenate or undulate. 



t Semicells pyramidate, lateral margins retuse or sub- 

 retuse, very rarely straight. 

 Apex of semicells truncate or subtruncate. 

 Basal angles broadly rounded. 



34. C. succisum. 



35. C. subretusiforme. 



36. C. retusiforme. 



37. C. Hammeri. 



38. C. Nymannianum. 

 Basal angles rectangular. 



39. C. trilobulatum. 



40. C. granatum. 



41. C. Pokornyanum. 

 Apex of semicells very convex. 



42. C. pseudatlantlwideinn. 

 ft Semicells pyramidate, lateral margins convex, rarely 



straight. 



J Cells never more than 1^ times longer than broad. 

 Semicells pyraniidate-seniicircular. 



43. C. subtumidum. 

 Semicells pyraniidate-trapeziform. 



44. C. yaleritum. 



45. C. pseudonitidulum. 



46. C. nitidulum. 



VOL. II. 9 



