CYCLOSTOMATA 



the upper slightly concave and celluliferous. 

 circular ap<-rtmv>, radially airan-cil 

 on the summits of low ridges. Y-ry 

 -tive of yl /'-< n't' *(. Certain 

 Chazy species are composite, and allied 

 to Ceramoporella. Ordovician. 



Spatt'oj,,,,;; ririch (Fig. 441). 

 Zoaria forming thin crusts, especially 

 on Orthoccras. Apertures irregular; 

 lunarium scarcely perceptible. Meso- 

 pores, when present, chiefly in 

 maculae. Interspaces often with 

 large blunt spines (? acanthopores). 

 Ordovician. 



ZM , ja with slightly oblique, sub- 



Flo. 441. 



.Ulr. Cincinnati Group ; Hamilton, (). 

 .1, Surlar.-. /;, Vertical section. (,', Tangential section; all 

 14/j (after Ulrich). 



Family 10. Fistuliporidae. Ulrich. 



Zoaria massive, Inn him; or ramose, the surface exhibiting at regular intervals " maculae " 

 or "monticules" composed of clusters of vesicles and of zocecia slightly larger than the 

 average. Lunarium more or less developed. Zocecial tubes never angular, thin-walled, and 

 with horizontal diaphragms ; apertures closed by perforated operculum. Interspaces occupied 

 by vesicular tissue. Cell walls minutely porous. Silurian to Permian ; climax in 

 Devonian. 



Waagen and Wentzel have recently referred this family to the Corals (cf. ante, p. 105), but 

 their reasons for doing so rest obviously upon insufficient observation. Not only are the 

 members of this family derived from the Ceramoporidae, as noted above, which are undoubted 

 Bryozoans, but some of them possess ovicells, thus abundantly proving their Bryozoan nature. 



Fidnlipora, M'Coy (Lichenalia, Thallostiyma, Hall ; Didymopora, Ulrich; Dybow- 

 skiella, Waag. and W.), (Fig. 442). Zoaria massive, lamellate, more rarely ramose, 

 parasitic, or free ; under surface with wrinkled epitheca. 

 Zooecia sub-radially arranged about the surface maculae ; 

 apertures ovoid, sub-triangular, or pyriform, according 

 to the degree in which the lunariuin is developed ; 

 interiorly with thin walls, and a small number of com- 

 plete horizontal diaphragms. Interspaces smooth or 

 granular, occupied internally by one or more series of 

 vesicles. Common from Silurian to Sub-Carboniferous ; 

 less frequent in Coal Measures 

 and Permian. 



Cyclotrypa, Ulrich (n. gen. 

 or sub-gen.), (Fig. 443). Like 

 Fistulipora, but the lunarium 

 obsolete, and zocecial tubes 

 circular in transverse section. 

 Devonian. Fist, communis and 

 F. collina, Ulrich. 



Eridopora, Ulrich (Pileotrypa, 



Hall). Zoaria thin, parasitic. Hamilton ; Nt-w Buffalo, Iowa. 

 r, -,1 IT i Tangential section, "A. 



Zooecia with oblique, sub- 

 triangular, or ovoid apertures. Lunarium very prominent. 



Chilotrypa, Ulrich (Coelocaulis, Hall). Zoaria small, ramose, with a narrow, 

 irregularly contracting and expanding axial tube. Apertures elliptical, oblique, the 

 lower margin thick and elevated, the wall thin above. Diaphragms few or absent. 



Ulr. 



Cyclotrypa communis, Ulr. 

 Hamilton ; New Buffalo, Iowa. 

 Vertical and tangential sections, 

 w/i (after Ulrich). 



Niagara to Coal Measures. 



