170 MONOGRAM OF THE FOSSIL POLYZOA OF THE 



has never heretofore been known to occur below the Upper Green Sand, (Cenomanien), 

 where only one species has been characterized, as far as we are aware. 



CAVID^. 



Intermediate pores between the cellules ; usually opposed pores on one side. 



LICHENOPORA, Defr. 



* 



Colony discoidal, free. Cellules placed in multiserial radiating lines on one side, 

 with numerous intermediate pores between the lines ; opposite side covered with an 

 epithelium, or germinal plate, without " opposed pores." 



The presence of an epithelium and absence of "opposed pores" distinguish this 

 genus from Bicavea. The fact of having a number of rows of cellules in each line 

 separates it from Discocavea, in which the lines are uniserial. Its being free, instead 

 of encrusting, distinguishes it from Radiocavea and Stellocavea, while from the dis- 

 coidal forms of the Tubigeridce it can be separated by having intermediate pores. 



L California, fig. 68. Id., Con., Proc. Acad. Nat. Sci. Phila. 1855, p. 441. 



Colony irregularly discoidal, sometimes twisted. Cellules arranged in not very 

 regular, prominent, radiating lines often commencing or ending abruptly and with 

 new ones interpolated. Two or three rows of cellules usually in each line. Cellules 

 tubular, crowded, circular when not compressed. Central third of the colony de- 

 pressed and occupied only by " intermediate cellules." These vary much in size and 

 form, and generally have a regular concave margin, bounded by straight lines, with a 

 rounded opening. Pores between the rows of cellules smaller, more crowded and less 

 concave. Germinal plate extending prominently beyond the edge of the cellulate 

 portion of the colony, and showing numerous germs of new cellules. Back of the 

 colony concentrically striate and marked by fine radiating lines. 



Rare. Santa Barbara, Cal. Miocene. 



Div. IV. C. FORAMINATA. 



Cellules simply pierced, not tubulate. 



Pam. GAVIDM 

 Openings of the cellules simple, not infundibulate. No intermediate pores. 



REPTOMULTICAVA, d'Orb. 



Colony encrusting, composed of many layers of cellules superposed. Cellules simply 

 pierced, not tubulate. Cellular surface not ribbed nor marked by nodes without cel- 

 lules. 



This genus resembles several others, but can be distinguished by being always en- 



