O KANSAS UNIVERSITY QUARTERLY. 



mm., with from five to six occurring in 5 mm. Zoecia in three or four 

 alternating ranges, which number is often reduced to two for a very 

 short distance after a bifurcation. The typical number of ranges is 

 three when the central row forms the flat median summit of the 

 branch. In this case the number is increased to four shortly before 

 bifurcating. Apertures small, subcircular, about one and one-half 

 times their diameter apart longitudinally. The rows of apertures are 

 separated by inconspicuous undulating ridges, which are at intervals 

 elevated to form small nodes, about as numerous as the apertures. 

 The ridges are more prominent in worn specimens. On the reverse, 

 the dissepiments and the branches are on the same plane. The latter 

 are finely striated. 



Position and locality: Upper Coal Measures; Kansas City, Mo., 

 Argentine, Lawrence, and Topeka, Kan. Type in author's collection. 



The only species with which this is liable to be confounded is P. 

 nodocarinata Ulrich. In our species, the typical number of zoecial 

 ranges is three rather than four. The branches are somewhat flexuous 

 and not straight. The carinate appearance is not so marked and the 

 nodes are not so prominent. The number of branches and fenes- 

 trules in 5 mm. is another distinction between the two species. This 

 is one of the commonest species of bryozoans in the collections 

 studied, and is quite variable in its characters. Some of the speci- 

 mens are much more closely related to P. nodocay'inata than others. 

 Polffjiora fri(fH(/Nl(iris, n. sp. Plate IV, figs. 3-3e. 



Zoarium a foliar expansion of unknown size, forming a loose net- 

 work. Branches strong, slightly flexuous, about seven in 1 cm.; cross- 

 section subtriangular, resembling a sector of a circle. The width of 

 the branches is about 0.8 ram. Obverse side only moderately convex, 

 with subangular margins. Dissepiments rather long, of variable 

 width, rounded, depressed, spreading .slightly at each end and often 

 faintly striated. Fenestrules large, subquadrangular, as wide as the 

 branches, and about three times as long, averaging 2.5 mm. by 0.8 mm. 

 Three or three and one-half occur in a space of 1 cm. Zoecia usually 

 in five or six ranges, but just after a bifurcation there are only three 

 or four. Apertures circular, with moderately strong peristomes, in- 

 complete at their lower margins, like those of Thamniscus octanarius 

 Ulrich. In worn specimens this feature is not apparent. Apertures 

 small, from two to three times their diameter apart, about fourteen in 

 5 ram., arranged in quite regular diagonally intersecting series. 

 Measuring diagonally, four apertures occur in 1 mm. On the reverse 

 the branches are subcarinate, and bear a single row of prominent 

 nodes, placed about one and one-half times their diameter apart, with 

 from six to eight for each fenestrule. 



