NO. 5 ORDOVICIAN BRYOZOA BOARDMAN I3 



dence for a phyletic or descriptive relationship between the genera. 

 The collection of the U. S. National Museum also includes a species 

 of Anaphragma identified as A, mirahile from the Fern vale formation 

 near Pulaski, Tenn., and two other forms of Anaphragma identified 

 as A. mirahile Bassler, 191 1 (p. 298) and A. mirabile cognata Bassler, 

 191 1 (p. 299), from the highest Middle and Upper Ordovician of 

 Esthonia. Sections w^ere made of some of the specimens identified as 

 A. mirahile from Delafield and Iron Ridge, Wis., in the original 

 description of the species, but the internal structure is completely 

 gone and no identification can be made. 



ANAPHRAGMA MIRABILE Ulrich and Bassler 



PI. 3, figs. 1-4; pi. 4, figs. 1-4 



1904. Anaphragma mirabile Ulrich and Bassler, Smithsonian Misc. Coll., vol. 

 47, No. 1470, p. 49, pi. 13, figs. 9-11. 



Material studied. — The cotype suite, U.S.N.M. 43218, from the 

 Richmond group, Wilmington, 111., includes a sectioned specimen here 

 designated the lectotype, six specimens that are considered con- 

 specific with the lectotype after sectioning, and five specimens of an 

 undescribed species of Batostoma that is a close external homeo- 

 morph of A. mirabile but is quite different internally. 



In addition, 21 topotype specimens were studied from the following 

 collections : 



U.S.N.M. 2996: Richmond group (approximately 10 feet of beds 

 exposed) on west bank of Kankakee River, just north of U. S. 66A 

 bridge, Wilmington, Illinois. Collected by A. R. Loeblich, Jr. 



U.S.N.M. 2997 : Richmond group, Wilmington, Illinois. Collected 

 by E. O. Ulrich. 



New U.S.N.M. catalog numbers 138273 to 138280 are assigned 

 to individual primary types and topotypes ; the lectotype is 138275. 



Description. — Zoaria are ramose ; branches are generally circular in 

 cross section. Conspecific overgrowth is poorly developed, occurring 

 on three specimens in very thin patches. Monticules are low and 

 difficult to distinguish externally. 



In the endozone, zooecial walls range from straight to irregularly 

 undulated and display a considerable variation in thickness. The 

 zooecial walls are laminated and adjacent zooecia are separated by 

 dark zooecial boundaries running down the centers of the walls. These 

 boundaries merge distally into the zooecial boundaries of the early 

 exozone. 



In the early exozone as seen in longitudinal sections, zooecial 



