4^ CLASS I.— ORDER I. 



22. Cellepora PaUadatia, Cells oval, slightly 

 convex, and punctured ; openings round above, and 

 transverse-oblong in the lower part. 



Mediterranean. 



23. Cellepora Bomiana, Cells alternate and trans- 

 parent ; the opening an almost four-sided oval, drawn 

 in at two of the sides, and closed by a small mem- 

 brane slightly punctured. 



Mediterranean. 



24. Cellepora otto-mnlleriana. Cells a little con- 

 vex and opaque ; the opening a longish oval, closed 

 by a smooth membrane. 



Mediterranean. 



FLUSTRA. 



Crustaceous Polypidoms, or of a leafy appear- 

 ance, horny or nearly membranous, consisting of short 

 tubular polypiferous cells, placed at the side of each 

 other, and disposed in regular series on one or more 

 surfaces. 



That character of existing union, which, in our in- 

 troductory history of Polypidoms, we observed was the 

 chief peculiarity by which Polypidoms could be defined, 

 seems to claim an exception with the Celleporas, and 

 also with the Flustras, whose polypi, in their mem- 

 brano-calcareous cells, appear distinct and unconnect- 



