BRYOZOA. 403 



STREBLOTRYPA Ulrich. Zoaria ramose, slender, solid. Zooecia 

 radiating from an imaginary axis, their primitive portion long, 

 tubular ; or from a linear axis when they are somewhat shorter. 

 Inferior hemisepta best developed, situated rather far down. 

 Apertures regularly elliptical, or somewhat truncated at the 

 posterior margin, surrounded by a slight peristome and, within 

 this, sometimes a narrow sloping area; arranged usually in 

 rather regular longitudinal series. Just back of the aperture, 

 occupying the depressed front of the cell, there are from one to 

 twelve or more small pits, which, when numerous, are arranged 

 in two or three rows. Very small acanthopores occasionally 

 present. 



Type: S. nicklesi n. sp. Range, Hamilton to Chester. 



WORTHENOPORA n. gen. Zoaria bifoliate, branching or pal- 

 mate. Zoopcia very regularly arranged, sub-tubular, or rather, 

 elongate rhomboidal, with the aperture semi-elliptical. On the 

 surface the line of junction between the cells is marked by an 

 elevated ridge. The truncated posterior margin of the aperture 

 is raised into a less strong transverse bar. The elongate trian- 

 gular depressed front appears perfectly plain. 



Type: W. spinosa n. sp. Range, Keokuk to St. Louis. 



CYCLOPORA Prout. Zoaria unilaininar, parasitic or free. Pri- 

 mitive portion of zooecia. sub-tubular. Apertures sub-circular or 

 somewhat truncated posteriorly, surrounded by a moderate, 

 granose or smooth, peristome; arrangement various. When 

 regularly developed there is a large oblong more or less shallow 

 depression between each four adjacent zooecia. With a less regu- 

 lar development, this space may be divided into two smaller 

 ones; or it may appear that the apertures are separated by 

 unequal and irregularly situated depressions. With growth 

 these interspaces are drawn out into tabulated mesopores. 

 (PI. LXYIII, fig. 3f.) Hemisepta very little developed. 



Type: C. fungia Prout. Range, Keokuk and Warsaw beds. 



PROUTELLA n. gen. Zoarium discoid, thin, free, the lower sur- 

 face convex and lined with a concentrically wrinkled epitheca. 

 Primary zocpcia sub-tubular, the succeeding ones shorter, all 

 rather thin-walled. Aperture broad-elliptical, surrounded by a 

 very narrow sloping area, hexagonal in outline; when perfect, 



