196 



Cincinnati Society of Natural History. 



NEMATOPORA GRANOSA, n. Sp. 



Fig. 20. — Xcmatopora granosa, n. sp. a, uubranched fragment xl8, .with five rows 

 of zocecia, showing the granulose angles and interspaces, and narrow zooecial aper- 

 tures, b, end view of same, c, bifurcating fragment xl8, with the rows of granules 

 slightly flexuous. d, slightly worn fragment with only four rows of zocecia. e, end 

 view of same. 



Zoarium ramose: branches bifurcating at rather long intervals, 

 from 0.25 to 0.38 mm. in diameter, the smallest quadrangular in 

 cross-section and with only four rows of zooecia; those of the 

 average size, pentagonal, and with five rows of cells. Zocecial 

 apertures small, narrow, about seven in each range in 2.5 mm., 

 enclosed by a series of minute granules. Longitudinal interspaces 

 with a small number of similar granules. Rows of apertures sep- 

 arated by more or less well-developed straight or slightly flexuous 

 granulose ridges. 



The papillose ornamentation and narrow zocecial apertures of 

 this species distinguish it from all the others known to me. There 

 is considerable external resemblance to small species of Rhombopora 

 like R. lineinodis, Ulr. , and R. regularis ( Trematopera regularis and 

 Orthopora regularis, Hall), but not much in the more important 

 internal characters. 



Position and locality: Top of Trenton Shales, Cannon Falls, 

 Minn. 



