NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
331 
1887. Oemellipora striatula MacGillivray, Bryozoa in McCoy’s Prodromus of the Zoology 
of Victoria, vol. 2, dec. 14, p. 150, pi. 138, fig. 10. 
1888. Schizoporella venusta Kirkpatrick, Polyzoa of Mauritius, Annals Magazine Natural 
History, ser. 6, vol. 1, p. 76. 
1890. Schizoporella venusta Kirkpatrick, Hydroida and Polyzoa from the China Sea, 
Annals Magazine Natural History, ser. 6, vol. 5, p. 17. 
1890. Schizoporella venusta Kirkpatrick, Proceedings Royal Society Dublin, n. s. vol. 6, 
p. 612. 
1899. Schizoporella striatula Phillips, Report on the Polyzoa from Loyalty Isles, New 
Guinea and New Britain, Zoological Results, A. Willey, pt. 4, p. 440. 
1902. Trypostega venusta Levinsen, Studies on Bryozoa, Vidensk Medd. fra den Naturh. 
Foren. i Kjpbenhaven, p. 23. 
1907. Schizoporella venusta Calvet, Expedition Scientific du Travailleur et Talisman, vol. 8, 
p. 416. 
1909. Trypostega venusta Levinsen, Morphological and Systematic Studies on Cheilosto- 
matous Bryozoa, p. 281, pi. 19, figs, la-ld; pi. 22, figs. 13a-13d. 
1909. Trypostega venusta Norman, Polyzoa from Madeira, Journal Linnean Society Zoology, 
vol. 30, p. 299. 
1912. Gemellipora glabra, form striatula Thornely, Marine Polyzoa Indian Ocean, Trans- 
actions Linnean Society Zoology, vol. 15, p. 149. 
1913. Trypostega venusta Waters, The Marine Fauna of British East Africa and Zanzibar, 
Proceedings Zoological Society London, p. 506. 
1914. Trypostega venusta Osburn, The Bryozoa of the Tortugas Islands, Florida, Publica- 
tion Carnegie Institution Washington, No. 182, p. 198. 
Measurements. — Aperture 
^ < 2 = 0 . 08 - 0.10 mm. 
7a=0.06-0.08 mm. 
Zooecia 
[ Zs=0.40-0.46 mm. 
{ 7s=0.26-0.30 mm. 
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 (Aa=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 aquitanica 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 our fossil specimens 
resemble the recent one absolutely. 
Occurrence. — Vicksburgian (Byram marl) : Bvram, Mississippi (rare) ; one- 
fourth mile west of Woodward, Wayne Count} 7 , Mississippi (rare). 
