SUB-ORDER C 



CRYPTOSTOMATA 



283 



Thamniscus, King. Like Polypora, but branches bifurcating more freely, and with 

 only a few dissepiments or none. Silurian to Permian. 



Phyllopora, King. Zoaria lunm-Miaped, celluliferous on the outer side, and con- 

 sisting of anastomosing branches, \\lii.h form a regular, round -meshed network. 

 Zoojcia in two or more rows. Devonian and Permian. 



Ptiloporella, Ptiloporina, Hall. Silurian and Devonian. 



Ptilopora, M'Coy (Dendricopora, de Kon.) Zoaria pinnate, the central branch much 

 stronger than the oblique lateral branches, which are united by dissepiments. Zoo2cia 

 in two ranges. Devonian and Sub-Carboniferous. 



Family 7. Acanthocladiidae. Zittel. 



Zoaria poriferous on one side only, pinnate or forming fenestrated expansion ; consisting 

 of strong, central stems which (jive off numerous, smaller, lateral branches from their opposite 

 maryins. The lateral branches are free or unite with those of the next stem. Non- 

 poriferous dissepiments absent. Zocecial characters mostly as in the Fenestellidae. Silurian 

 to Permian. 



J'tunatopora, Vine (Glauconeme, auct.) Zoaria small, delicate, with short, free, 

 lateral branches given off frequently at regular intervals. Cells in two rows, one on 

 each side of a moderate median keel. 

 Silurian to Carboniferous. 



Septopora, Prout. Zoaria fenes- 

 trated, flabellate, or leaf-like. Primary 

 branches numerous, increasing by bi- 

 furcation or interpolation ; the lateral 

 branches uniting with those of adjacent 

 stems. Reverse usually with fine striae 

 and scattered dimorphic pores. Cellu- 

 liferous side with two rows of zocecia 

 arranged as in Pinnatopora. Chester 

 Group and Coal Measures. 



Acanthocladia, King. Like Pin nato- 

 pora, but larger, stronger, and with 

 three or more ranges of cells. Coal 

 Measures and Permian. 



Synocladia, King. Differs from Septopora in the same manner as the preceding 

 differs from Pinnatopora. Permian. 



Diplopora, Young. Essentially a Pinnatopora without lateral branchlets. Carboni- 

 ferous. 



Ichthyorachis, M'Coy, Penniretepora, d'Orb., and Ramipora, Toula, may belong here. 



FIG. 469. 



Hdopora spiniformis, Ulr. 

 Tn-nton; Tennessee. A, Ver- 

 tical section, 1%. Ji, Segment, 

 Vl and 14/j (after Ulrich). 



Fio. 470. 



Pachydictya foliata, 

 Ulr. Lower Trenton ; 

 Minnesota. Tangential 

 section, u/i (after 

 Ulrich). 



Family 8. Phylloporinidae. Ulrich. 



Zoaria branching, celluliferous on one side only, the other side striated ; branches free or 

 anastomosing. Zocecia more or less tubular, often with diaphragms. Hemisepta wanting. 

 Ordovician to Coal Measures. 



Phylloporina, Ulrich. Branches irregularly anastomosing, with two to eight 

 ranges of zooecia on the celluliferous side. Tabulated interstitial spaces generally 

 present, closed at the surface. Ordovician and Silurian. 



Drymotrypa, Ulrich ; Ordovician and Silurian. Chainodictyon, Foerste ; Coal 

 Measures. 



The following genera of doubtful affinities may be provisionally appended here : - 

 Proutella, Cycloporella, Worthenopora, Ulrich ; Cyclopora, Prout ; Paleschara, Hall. 



