BRYOZOA. 383 



MEEKOPORA Ulrich. Zoaria bifoliate, sometimes branching; 

 the median lamina? thin, flexuous. Zooecia not arranged : in 

 radial series around the solid maculae, but with their oblique 

 apertures directed towards the distal margin of the expansion. 

 Lunarium moderate or obsolete. Zocecial tubes oblique, the 

 anterior walls thinnest and flexuous. Diaphragms numerous, 

 often recurved. Ooeciuni a large oval cell, showing as a convex 

 space with a small apical perforation. 



Type: M. eximia Ulrich. Range, Keokuk, St. Louis and Ches- 

 ter. 



STROTOPORA Ulrich. Zoarium ramose, branches large, irregu- 

 lar, solid or hollow. Large abruptly spreading cells, which are 

 supposed to represent ooecia, are distributed among the ordi- 

 nary zooecia. When well preserved they appear on the zoarial 

 surface as strongly convex nodes, about 0.5 mm. in diameter, 

 with an opening on one side. 



In all other respects like Fistulipora^ 



Type: S. foveolata Ulrich. Range, Devonian to Lower Car- 

 boniferous. 



LICHENOTRYPA Ulrich. Zoaria thin, incrusting, with two dis- 

 tinct stages of development. In the first the colony resembles 

 an ordinary species of Fistvlipora, the zooecia having subcircu- 

 lar apertures, surrounded by a peristome that is thickest and 

 most elevated on the posterior side, the interspaces concave and 

 smooth. As growth proceeds, the peristomes of the adjacent 

 zooecia are united by thin irregular walls, which traverse the 

 interspaces and gradually form an elevated and very irregular 

 net -work, with still greater elevations at numerous points in 

 the shape of strong spines. Many of the zocecia keep pace with 

 the formation of this superficial structure, while others occup\ r 

 the bottom of large cavities. Numerous subangular pores or 

 vesicles are interspersed among the zooecial apertures; the two 

 kinds of cells not easily distinguished. 



Type and only specie's known: L. cavernosa Dlrich. Middle 

 Devonian. 



BUSKOPORA Ulrich, (Odontotrypa Hall, Glossotrypa Hall, 

 Pileotrypa Hall (pars). Zoaria thin, lamellate, incrusting or free. 



