NORTH AMERICAN EARLY TERTIARY BRYOZOA. 753 



Genus TUBULIPORA Lamarck, 1816. 



]S16. Tubulipora, LAMARCK, Historic naturelle des auiniaux sans vertebres, vol. 2. 

 The ovicell is irregular, lobed, spread out between tlie fascicles. The tubes 

 are quite salient, isolated or joined in fascicles, uniserial and irregular. The oecio- 

 stome is adjacent to a tube and the oeciopore is directed in a direction contrary to 

 that of an apertura. Eleven or 12 tentacles. Gemmation generally peripheral. 

 Genotype. Tubulipora fiabcttaris Fabricius, 1780. 

 c. Midwayan-Recent. 



Harmer 1 defines the genus as follows : 



Zoarium with a distinct basal lamina, adnate or erect, beginning as a pyriform or 

 flabelliforin colony, which may become lobed by tbe division of tbe terminal membrane. Lobes 

 short and adherent, or longer and dicbotomonsly divided once or more often, sometimes be- 

 coming erect. Zooecia with a free, cylindrical, terminal portion ; or connate in obliquely trans- 

 verse series, in which they are separated by flat septa corresponding with the intersection of 

 two cylindrical zooecia. The series are arranged alternately on opposite sides of the axial 

 line of the lobe, but the transverse arrangement usually becomes radial in the distal part of 

 the fertile lobes. Ovicell, an enlarged zooecium, which extends into the intervals between 

 the parallel or radial series. 



Genotype. Tubulipora UUacca Pallas, 17GG. (=TubuHpora serpens authors). 

 Canu in 1916 explained why the change of Tubulipora serpens to Tubu- 

 lipora liliacea is not acceptable. Moreover, this species is badly chosen as geno- 

 type of the genus, for it is the only one which has an idmoneiform zoarium ; all 

 the other species are more or less flabellatc. We would rather prefer the Tubuli- 

 pora fldbellaris Fabricius, 1780, very well figured later, as the true genotype. 

 It is indeed true that Tubulipora serpens is a Tubulipora. The genus Idmonea 

 Lamouroux, 1821, is also quite distinct and is characterized by the form and position 

 of its oeciopore. 



TUBULIPORA MIDWAYANICA, new species. 



Plate 107, fig. 1. 



Descri-ption. The zoarium is flabellate, small, free, living on algae. The fas- 

 cicles are salient, crowded, uniserial, complete, radiating from the ancestrula. 

 The tubes are invisible ; the peristome is thin, round or polgonal. 



Diameter of the peristome ____________________ 0.08 mm. 



Diameter of the apertura __________________ : ____ 0.06 mm. 



Distance between the peristomes _______________ 0.10 mm. 



Affinities. The only specimen found has been figured. The necessities of the 

 generic classification oblige us to describe it, but it is difficult to establish its rela- 

 tions with the other known species, especially since it has no ovicell. 



It differs from Tubulipora fabeUaris Fabricius, 1780, in its complete and non- 

 interrupted lines and in its much shorter tubes. 



Occurrence. Midwayan (Clayton limestone) : One mile west of Fort Gaines, 

 Georgia (very rare). 



Holotype.G&i. No. 65243, U.S.N.M. 



1 1898. Harmer, On the development of Tubulipora, Quarterly Journal Microscopical Society, n. s, 

 vol. 41, p. 99. 



55899 20 Bull. 106 - 48 



Measuremen ts. 



