178 BULLETIN 11, UNITED STATES NATIONAL MUSEUM. 



FamUy HETEROTRYPIDiE Ulrich. 



Heterotrypa Nicholson. Petigopora Ulricli. 



^Dekayella Ulrich. *Leptotrypa Ulrich. 

 Cyfhotrypa Ulrich and Bassler. Atactopora Ulrich. 



Dekayia Edwards and Haime. ^Stigmatella Ulrich and Bassler. 



FamUy CONSTELLARIIDiE Ukich. 



^Constellaria Dana. Idiotrypa Ulrich. 



^SteUipora Hall. *Dianulites Eichwald. 



* Nicholsonella Ulrich. 



FamHy BATOSTOMELLID^ Ulrich. 



*Byt7iopora Miller and Dyer. ^LiodemeUa Foerste. 



*Eridotrypa Ulrich. "^^Orhipora Eichwald. 



^Lioclema UMch. **Esthoniopora, new genus. 



Division ITTTEGBATA TJlricIi and Bassler. 



Trepostomata in which the boundaries of adjoining zocecia are 

 sharply defined by a black divisional line: 



Family AMPLEXOPORID^ Ulrich and Bassler. 



Amplexopora Ulrich. RJiomhotrypa Ulrich and Bassler. 



Monotrypella Ulrich. *Petalotrypa Ulrich. 



FamHy HALLOPORID^, new name. 



*HaTlopora, new name. Calloporella Ulrich. 



Calloporina Ulrich and Bassler. 



FamHy TREMATOPORIDiE Ulrich. 



* Trematopora Hall. ^' HemipTiragma Ulrich. 

 ^Batostoma Ulrich. **DiUopora Dybowski. 



Stromatotrypa Ulrich. ^Diplotrypa Nicholson. 



*AnapJiragma Ulrich and Bassler. * Monotrypa Nicholson. 



Division AMALGAMATA UlricIi and Bassler. 



FamUy MONTICULIPORID^ Nicholson (emended Ulrich). 



The most important characteristic of this family, as emended by 

 Ubich, is the occurrence of the convex plates known as the cysti- 

 phragm. These curved structures are limited to the zooecial tubes, 

 where they form continuous series lining the walls. In most of the 

 genera the curve is complete, but in Orhignyella and Mesotrypa the 

 cystiphragms are often so slightly curved that they have the appear- 



^ 



