214 C. E. Beecher — Development of a Paleozoic Poi-iferous Coral. 



Plate XII. 



Pleurodictywii lenticulare. 

 Fig. 1. Outline of upper side of specimen with eight peripheral calices. x 3^. 

 Fig. 2. Upper side of symmetrical specimen; showing general features of calices, 

 mural pores in central eorallite, and thickened epithecal border, x 3|. 

 Lower Helderberg Group. Albany County^ New York. 



Plate XIII. 

 Pleurodictyum lenticulare. 

 Fig. 1. Calical diagram of geratologic specimen; showing enlargement of second, 

 fourth, and eighth corallites, and the addition of tertiarj^ cells, forming a 

 second series of peripheral calices. x 3^. 

 Lower Helderberg Group. Albany County, Neiv Torh. 



Pleurodictyum prohlematicum. 

 Pig. 2. Lower side of cast of corallum with epitheca removed ; showing proximal 

 extremities of several corallites. Upper edge of figure represents portion 

 of periphery of corallum. Thus, lower angle of each eorallite represents 

 the point of budding from parent cell, and is connected with it by a pore, 

 shown for three of the corallites by dotted lines from ^). It will be 

 noticed that all the pores in the angles are larger than the others. Otlier- 

 wise, these and the initial pores cannot be distinguished from the ordinary 

 mural pores between the flat sides of the corallites, x 7. 

 Devonian. Pelm, Germany. 



Favosites epidermatus ? 

 Fig. 3. Side view of mature eorallite with attached intermural bud. Specimen 



broken from interior of a large colony, x 3^. 

 Fig. 4. The same front view, with bud lemoved ; showing pore or mural opening (p) 

 at lower point of attachment of bud, corresponding to those indicated in 

 figure 2. X 3|. 

 Corniferous limestone. Cherry Valley, Neiv York. 



