EARLY PALEOZOIC BRYOZOA OF THE BALTIC PROVINCES. 339 



features indicative of the TrematoporidaB, but until more species are 

 known, I prefer to classify the present form as a doubtful Hallopora. 



Occurrence. — Common in the Wesenberg limestone (E) at Wesen- 

 berg, Esthonia, Less common in the Kegel limestone (D2) at Kegel, 

 Esthonia. 



Holotype.—Csit. No. 57481, U.S.N.M. 



Fig. 213.— Hallopoea ? tenthspinosa. a, an oudinaey fragment, natural size; b, tangential 



SECTION, X20, SHOWING A FEW SMALL ACANTHOPOEES; C, POETION OF THE SAME, X35, WITH THE STRUC- 

 TURE OF ZOQECIA AND ACANTHOPOEES MOEE CLEAELY EXHIBITED; d, VERTICAL SECTION, X20, WITH CHAE- 

 ACTERISTIC tabulation; e, POETION OF A TEANSVERSE SECTION, X20. WeSENBERG LIMESTONE 



(E), Wesenberg, Esthonia. 



A thin section of the type-specimen is in the collections of the 

 British Museum. 



UNDETERMINED GENERA AND SPECIES. 



Although I have attempted to identify all of the Russian Ordo- 

 vician forms previously described, it happens that there are still 

 quite a number so poorly defined and figured that I at least am able 

 to do nothing with them. In all of these cases, so far as I am aware, 

 the original types are either lost or are not distinguished. Should 



