EAELY PALEOZOIC BEYOZOA OF THE BALTIC PROVINCES. 59 



resented, although somewhat sparsely, in the Russian strata under 

 discussion. 



The much-debated Ceramoporidse and Fistuhporidse are more 

 numerously represented both in genera and species. These families, 

 considered by many authors as tabulate corals but by Ulrich as 

 trepostomatous bryozoans, were doubtfully referred by the latter in 

 1900 ^ to the Cyclostomata. Further studies have shown the wisdom 

 of this course, and I believe enough evidence can now be assembled 

 to estabhsh the Ceramoporidae and F«istuliporidse as undoubted 

 Cyclostomata. Both have the minutely porous wall structure of 

 typical members of the order, and, in addition, most of their genera 

 show ooecia exactly as in recent forms. 



Family DIASTOPORID^ Busk. 



Only the simplest of the diastoporoid genera are represented in 

 the Russian collections, and most of their species prove to be iden- 

 tical with American forms. The same condition holds for the 

 Idmoneidse and the Entalophoridse, but the remaining families, while 

 represented by the same genera, have in most cases new, although 

 analogous, species. 



Genus STOMATOPORA Bronn. 



Stomatopora Bronn, Pflanzenth., 1825, p. 27.— D'Orbigny, Pal. Francais, Terr. 

 Cret., vol. 5, 1854, p. 833. — Haime, Bry. Foss. Form. Jiiras., 1854, p. 159. 



Stomatopora (part) Pictet, Traite de Pal., ed. 2, vol. 4, 1857, p. 142. — Hincks, 

 British Marine Polyzoa, 1880, p. 424.— Zittel, Handbuch d. Pal., vol. 1, 

 1880, p. 598.^ — Ulrich, Joum. Cincinnati Soc. Nat. Hist., vol. 5, 1882, p. 

 149.— Vine, Proc. Yorkshire Geol. Polyt. Soc, vol. 9, 1887, p. 186.— Miller, 

 North American Geol. and Pal., 1889, p. 325.— Ulrich, Geol. Surv. Illinois, 

 vol. 8, 1890, p. 367; Geol. Nat. Hist. Surv. Minnesota, a^oI. 3, pt. 1, 1893, p. 

 115; Zittel's Textbook of Paleontology (Eng. ed.), vol. 1, 1896, p. 260.— 

 Simpson, Fourteenth Ann. Rep. State Geologist New York for the year 1894, 

 1897, p. 597.— Nickles and Bassler, Bull. 173, U. S. Geol. Surv., 1900, p. 

 20. — CuMiNGS, Amer. Joum. Sci., ser. 4, vol. i7, 1904, p. 75; 32nd. Ann. 

 Rep. Dept. Geol. Nat. Res. Indiana, 1907, p. 757. 



Aulopora (part) Goldfuss, Reuss, Hall, Nicholson. 



Zoarium of delicate, adnate, uniserially arranged, subtubular 

 zooecia with subterminal, exsert apertures and minutely porous walls. 



Genotype.— Stomatopora dichotow.a (I^amouroux). Jurassic of 

 Europe. 



Previous definitions of the genus Stomatopora have included the 

 simple unilinear species with clavate zooecia and with constricted 

 apertures. These have been recently classed under the new genus 

 Corynotrypa.'^ 



1 Zittel's Textbook of Paleontology, English edition, vol. 1, p. 267, 



2 Bassler, Proc. U. S. Nat. Mus., vol. 39, IQU, pp. 497-527. 



92602°— Bull. 77— 11 6 



