. Bulletin - United States National Museum. Science. EAELY PALEOZOIC BEYOZOA OF THE BALTIC PROVINCES. 333 monticules are separate, while in a few they are nearly obsolete. Zooecia with moder- ately thin walls, subangular or ovate apertures, of nearly equal size over all portions of the surface; 10 or 11 in 3 mm. Mesopores comparatively few, small, not readily distinguished externally, their mouths usually closed. Zooecial covers not observed. Occurrence.—Common in the Black River (Decorah) shales at Minneapolis and St. Paul, Minnesota, and in the Wassalem beds (D3) atUxnorm, Esthonia (Cat. No.
. Bulletin - United States National Museum. Science. EAELY PALEOZOIC BEYOZOA OF THE BALTIC PROVINCES. 333 monticules are separate, while in a few they are nearly obsolete. Zooecia with moder- ately thin walls, subangular or ovate apertures, of nearly equal size over all portions of the surface; 10 or 11 in 3 mm. Mesopores comparatively few, small, not readily distinguished externally, their mouths usually closed. Zooecial covers not observed. Occurrence.—Common in the Black River (Decorah) shales at Minneapolis and St. Paul, Minnesota, and in the Wassalem beds (D3) atUxnorm, Esthonia (Cat. No. 57469, ). British Museum, specimen and thin section from Fig. 209.—Hallopora tolu. a, small feagmekt, natural size; 6, tangential section, X20, show- ing LARGE, TmN-WALLED-ZOCECIA "WITH NUMEROUS MESOPORES; C AND d, TWO PORTIONS OF A VERTICAL SECTION, X20, EXHIBITING TABULATION. KUCKEES SHALE (02), REVAL, ESTHONIA, AND JEWE LIME- STONE (Dl), Bakon Toll's estate. HALLOPORA TOLLI, new species. Text fig. 209. This well marked species forms smooth, cylindrical branches 6 to 8 mm. in diameter, very much like H. wesenbergiana, but differing con- spicuously in having much larger zooecia. Internally the two are quite distinct, as a glance at the figures, especially of vertical sec- tions, will show. In tangential section, H. tolli exhibits its polygonal to rounded, thin-walled zooecia, four in 2 mm., with a fair number of small, angular mesopores. In the maculae the mesopores are occa- sionally numerous enough to isolate the zooecia, but elsewhere they are seldom so Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States National Museum; Smithsonian Institution; United States. Dept. of the Interior. Washington : Smithsonian Institution Press, [etc. ]; for sale by the Supt.
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