from the Kuchers Stage in Estkonia. 331 



Diagnosis. Zoarium dichotomously brandling with parallel 

 edges ; brandies in cross-section elliptical, with narrow, 

 non-celluli£erous, striated margins. Zocecial apertures ellip- 

 tical, in parallel longitudinal rows, separated by linear ridges, 

 without granules. 



Locality and Horizon. Kukruse, Esthonia. Middle Ordo- 

 vician, stage C 2 ; in the bituminous shale. 



Material. Figured specimen (rig. 8) in the British Museum, 

 Geological Dept., Regd. 1). 29832. Specimens in my 

 collection in the Geological Museum of the Universily 

 of Tartu (Dor pat). 



I)< script ion. The fragmentary zoaria of my specimens 

 possess zcoeeia on both sides, branching dichotomously. The 

 branches are 2-2*5 mm. wide. The length of the figured 

 zoaiial fragment (rig. 7) is 22 mm. 



The zocecial apertures are elliptical, a very few are slightly 

 pointed. The apertures have a thin-walled peristome. Longi- 

 tudinally to the axis of the zoarium, within 2 mm. are 3*5-4 

 apertures. The zooeeia are in longitudinal parallel rows ; 

 they are separated from each other by spaces equal to the 

 half <>f their longer diameter. On each side of the zoarium 

 are 7 or 8 rows of z cecia (fig. 8). The zooecial rows aie 

 separated from each other by tine linear ridges. The zoarium 

 is elliptical in cross-section, with sharpened striated margins. 



My specimens are in all respects very similar to the 

 American specimens of P. crassa figured by Bassler [loc. cit.). 



NematopOKA, Ulrich. 



E. 0. Ulrich, 1888, Amer. Geol. vol. i. p. 234. 



E. O. Ulrich, 1890, " Paleozoic Bryozoa," Geol. Surv. Illinois, vol. viii. 



pt. 2, pp. 401, 644. 

 R. S. Bassler, 1911, "Early Paleoz. Bryozoa of the Baltic Provinces/* 



Bull. U.S. National Mus. lxxvii. p. 155. 



JSematopora bo/oljubovi, sp. n. (PJ. VII. figs. 9, 10.) 



JHaynosis. Zucecia surround the cylindrical zoarium in 

 more or less parallel rows. Between the rows of the 

 elliptical zocecial apertures are fine canaliculate longitudinal 

 ridges ; these are divided by little transverse ridges into 

 squares. 



Locality and Horizon. Kukruse, Esthonia. Middle Ordo- 

 vician, stage C 2 ; rare in the bituminous shale. 



Material. Holotype in British Museum, Geological Dept., 

 Regd. 1). 2; 833. Paratype in my collection in the Geological 

 Museum oi the University of Tartu (Dorpat). 



