SYNOPTICAL CLASSIFICATION. 17 



** A single layer of cells. 

 t Polyzoarium reticulate. 



40. RETEPORA. 



ft Polyzoarium entire. 



41. HEMESCHARA. 



ft. Liberee. Polyzoarium unattached, usually discoid, conical or irregular. 

 Fam. 15. SELENARIID^. 



* Vibracula inter-serial. 



42. LUNULITES. 



** Vibracula intra-serial. 



43. CDPULAKIA. 



*** Vibracula scattered. 



44. SELENARIA. 



(c) Cells disposed around an imaginary axis. 



Fam. 16. VINCULARIIDM. 



45. VlNCULARIA. 



Or in a tabular form, as follows, in which those families, genera, &c., in which fossil 

 species occur, are printed in italics : 



