NORTH AMERICAN EARLY TERTIARY BRYOZOA. 331 



1SS7. Gemcllipora striatula MACGILLIVRAY, Bryozoa in McCoy's Prodromus of the Zoology 



of Victoria, vol. 2, dec. 14, p. 150, pi. 138, fig. 10. 

 1S8S. SchixoporeUa venusta KIRKPATKICK, Polyzoa of Mauritius, Annals Magazine Natural 



History, ser. 6, vol. 1, p. 76. 

 1890. SchKoporclla venusta KIRKPATRICK, Hydroida and Polyzoa from the China Sea, 



Annals Magazine Natural History, ser. 6, vol. 5, p. 17. 

 1890. ScJiixoporeUa venusta KIRKPATRICK, Proceedings Royal Society Dublin, n. s. vol. 6. 



p. 612. 

 1S99. Schizoporella striatitta PHILLIPS, Report on the Polyzoa from Loyalty Isles, New 



Guinea and New Britain. Zoological Results. A. Willey, pt. 4, p. 440. 

 1902. Tnjpostcga venusta LEVINSEN, Studies on Bryozoa, Vidensk Medd. fra den Naturh. 



Foren. i Kj0beuhaven. p. 23. 

 1907. ScTiizoporclla venusta CALVET, Expedition Scientific du Tnn-aiUrur et Talisman, vol. S, 



p. 416. 

 1909. Trypostcga venusta LKVINSEN, Morphological and Systematic Studies on Cheilosto- 



matous Bryozoa, p. 281, pi. 19, figs. la-Id; pi. 22, figs. 13a-13d. 

 1909. Tri/postega venusta NORMAN, Polyzoa from Madeira, Jourual Linnean Society Zoology, 



vol. 30, p. 299. 



1912. Crcmellipora glabra, form striatula THOHNELY, Marine Polyzoa Indian Ocean, Trans- 



actions Linnean Society Zoology, vol. 15, p. 149. 



1913. Trypostcga venusta WATERS, The Marine Fauna of British East Africa and Zanzibar, 



Proceedings Zoological Society London, p. 506. 



1914. Trypostcga venusta OSBURN, The Bryozoa of the Tortugas Islands, Florida, Publica- 



tion Carnegie Institution Washington, No. 1S2, p. 198. 



Measurements.-^^* i**' mm - Zooecia [f 



S mm. l?s= 



Affinities. Doctor Osburn has been kind enough to send us a recent specimen 

 from Beaufort, and we have thus been able to make all the comparisons with great 

 facility. . Undoubtedly our specimens belong to the recent species, everywhere very 

 cosmopolitan, although their micrometric dimensions are slightly smaller. 



The frontal pores are rather large and scattered. The zooeciules. are small 

 and pyriform : their orifice is orbicular and quite variable in size. 



This species differs from Trypostega undulata in which the dimensions are 

 very close, in its frontal perforated by a larger orifice (ha= 0.08-0.10 mm. instead 

 of 0.06-0.07 mm.), and in the absence of a rectangular rimule at the aperture. 



It differs from Trypostega inornata Gabb and Horn, 1862, in its perforated 

 frontal and its smaller micrometric dimensions (Lz smaller than 0.45 mm.). 



It differs from Trypostega aquitaniea Canu, 1906, in the absence of a distal 

 thickening at the peristome. This character is unimportant, and it may be that 

 the French species is only a variety of the recent form. 



Abrasion of the surface of the zooecia permits of the ready discovery of 

 dietellae (fig. 15) ; their number is variable; there are none around the zooeciules. 



The frontal gibbosity is not constant on the recent species; the specimen re- 

 ceived from Doctor Osburn notably, is deprived of it and oar fossil specimens 

 resemble the recent one absolutely. 



Occurrence. Vicksburgian (Byram marl) : Byram, Mississippi (rare) ; one- 

 fourth mile west of Woodward, Wayne County. Mississippi (rare). 



