THE FAMILY LITUOLID^ 147 



Genus Pohjpliragiiia, Eeuss. 



Test cylindrical, growing attached by the basal 

 extremity ; consisting of a line of very short cylin- 

 drical segments placed one above the other. Interior 

 of the chambers labyrinthic ; aperture terminal, cri- 

 brate (sieve-like). Cretaceous. 



Example. — P. crihruHinii, Reuss (LicJienopora), 

 ' Versteinerungen der bohm. Kreideformation,' pt. ii. 

 1846, pp. 60, 123, pi. xiv. fig. 10, pi. xxiv. figs. 3-5. 



The above species was found in the chalk forma- 

 tion of Bohemia by Reuss, and later by Perner in 

 the Cenomanian of that country. The afiinities of 

 the genus towards the semi-labyrinthic forms of 

 HcifJoplircujininm are seen in the internal structure 

 of the segments as revealed by thin sections of the 

 test, as well as by the nature of the septal face, which 

 is cribrate, as in IIa])Joplira(j)niuiii irregidare. The 

 species is found adherent to shells and Gidcvris spines. 

 Steinmann has referred this genus to the group of 

 the pharetrone sponges, but the minute structure of 

 the walls of the organism does not support this view. 

 Cretaceous. (Plate 7, figs. L, /.) 



Sub-fautil// 2. Teochamminin^. 



Test thin ; composed of minute sand-grains in- 

 corporated with calcareous or other inorganic cement, 

 or embedded in a chitinous membrane ; exterior 

 smooth, often polished ; interior smooth or (rarely) 

 reticulated ; chambers never labyrinthic. 



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