NICKLES AND BASSLEU.J TERMINOLOGY. 17 



Family I*tilodictyonidtu Ulrich. 



rtilodic'tya Lonsdale, Kscharopora Hall, Clathropora Hall, Phseno- 

 pora Hall. Artliropora Ulrich, Graptodictya Ulrich, Stictoporina 

 Hall. 



Family Stictoporellidge. 



IStictoporella Ulrich, Ptilotrypa Ulrich, Intrapora Hall, Coscinclla 

 Hall, Tteniodictya Ulrich, Stictopora Hall, Heliotrypa Ulrich. 



Family Rhinidictyonida' Ulrich. 



Rhinidictya Ulrich, Eurydictya Ulrich, Fachj^dictya Ulrich, Phyllo- 

 dictya Ulrich, Euspilopora Ulrich, Dicranopora Ulrich, Goniotrypa 

 Ulrich, Trigonodictya Ulrich. 



Family Cystodictyonidaj Ulrich. 



Cystodictya Ulrich, Dichotrypa Ulrich, Coscinium Keyserling, T^e- 

 niopora Nicholson, Thamnotrypa Hall, Semiopora Hall, Ptilocella 

 Simpson, Acrogenia Hall, Prismopora Hall, Scalaripora Hall, Glyp- 

 topora Ulrich, Phractopora Hall, Ceramella Hall, Evactinopora 

 Meek and Worthen, 'i Goniocladia Etheridge, Jun. 



Family Actinotrypidse Ulrich. 

 Actinotrypa Ulrich. 



Famih^ Cycloporidae. 



Cyclopora Prout, Cycloporella Ulrich, Proutella Ulrich, Wortheno- 

 pora Ulrich. 



Family RhinoporidEe Ulrich. 



Rhinopora Hall, Diamesopora Hall, Lichenalia Hall, Stictotr3q3a Ulrich. 



Suborder Chilostomata Busk. 



Family Palescharida3 Ulrich. 

 Paleschara Hall. 



TERMINOLOGY. 



ZoARiUM (polyzoarium, ccenoecium). — The composite structure 

 formed by repeated gemmation. The form which results is very vari- 

 able, though usually fairly constant for each species. Gemmation in a 

 plane produces nnilaminar sheets which are often parasitic (incrust- 

 ing) upon other organisms, but are sometimes free; in the latter case 

 the protecting covering on the under side is the epitlieca. Hollow 

 branches lined with an epitheca arc a special form of this mode of 

 Bull. 173 ii 



