PLATE XVII. 



MiCHELINA ClAPPI. 



Chonostegetes Clappi Edw.-Haime. Polyp. Fosj. Terr. Pal., p. -'99, pi. U. fi^s. i, 48. 1851. 

 Compare Michelina interinitleiis Billings. Oaiiad. Journ., New Series, Vol. IV, p. 113. 1859. 



" Haiineophylliim nrdinatuni Billings. Caiiad. Journ., New Series, Vol. IV, p. 139. 1859. 

 " EmiHon-'iia' ci/Undiica Kdw.-Hiume. Polvp. Foss. Terr. Pal., p ;J45. 18.51. 



Fig. 1. The upper side of an irregular subliemi.spheric ra.iss where the orilices of the cells are 

 somewhat free and apparently circular from the constrictions of the interior. In this 

 condition it may be similar to tlie form described by Billings, as Michelina intermit- 

 tens. Some portions of the same specimen show the peculiar characters of Chonoste- 

 getcs, which are more fully shown in figs. 2 and 3. The illustration of the various 

 phases of this coral will appear in the final pubHcation of the corals in the Paheon- 

 tology of New York. 



Fig. 2. A group of columns from a large mass, showing the constrictions at intervals, with the 

 expansion.s, like diaphragms, connecting the whole together. These are simply the 

 fillings of the circular constricted cells of specimens similar to the preceding, the coral 

 walls having been dissolved away. 



Fig. 3. The ends of the columns as shown on tlie upper side of the preceding specimen. This 

 specimen is from the Picket collection in the State Museum, and probably from the 

 neighborhood of Caledonia in Livingston county. 



Solid mas.ses, presenting circular depressions or cell-apertures are common in the 

 Upper Helderberg Limestone, in various parts of New York. Ol grinding and 

 polishing these, the angular cell-walls are shown with the circular form within them. 



Michelina fatosoidea. 



Michelina favosoidea Billings. Can.ad. Journ., New Series, Vol. IV, p. Hi. 1859. 



Fig. 4. A fragment of a larger ma.ss with open cells and continuous hoi'izontal diaphragms. The 

 pores of the cell-walls are not visible. 



