34 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 69 



Myriosoum Donati, 1750. Family Myriozoidae. 



Mystriopora Lang, 1915. Family Electrinidae. 



Nannopora Lang, 1916. Family Andrioporidae. Cretaceous cribriraorph. 



Naresia Wyville Thompson, 1873. Synonym of Kinetoskias. 



Nellia Busk, 1852. Family Farciminariidae. 



Nematopora Duvergier, 1921 (preoccupied). See Nematoporella. 



Nematoporella, new name. Family Opesiulidae. 



Neoeuthyris Bretnall, 1921. Family Euthyridae. 



Nephropora Marsson, 1887. Pal. Abh., vol. 10, p. 90. Type and only known 

 species N. elegans Marsson. Family Nepbroporidae Marsson, 1887. 



Nichtina. Canu, 1900. See Nitscheina. 



Nimba Jullien, 1903. Family Crepidacanthidae. 



Nimbella Jullien, 1903. Family Crepidacanthidae. 



Nitscheina {Nichtina in error) Canu, 1900. Family Electrinidae. 



Normanellina Cossman, 1920. Synonym of Conopemn. 



Notamia Fleming, 1828. Synonym of Eucratea. 



Notoplites Harmer, 1923. Family Scrupocellariidae. 



Ochetosella Canu and Bassler, 1917. Family Stomachetosellidae. 



Odontionella Canu and Bassler, 1917. Family Aspidostomidae. 



Ogiva Jullien, 188L Family Opesiulidae. Genotype Eschara actea D'Orbigny, 

 1851. Cretaceous. An inexact Cretaceous genus. 



Ogivalia Jullien, 1881. Family Opesiulidae. Cretaceous. Genotypes, Vincu- 

 laria elegans D'Orbigny, 1851 and Eschara santonensis D'Orbigny, 1851. 

 An inexact genus. 



Ogivalina Canu and Bassler, 1917. Family Hincksinidae. 



Oligotopora Lang, 1916. Family Andrioporidae. Cretaceous cribrimorph. 



Oligotresium Gabb and Horn, 1862. Synonym of Lunularia. 



Omalosecosa Canu and Bassler, 1925. Family Celleporidae, 



Omoiosia, new genus. Family Membranicellariidae. 



Onchopora Busk, 1855. Family Onchoporidae. 



Onchoporella Busk, 1884. Family Onchoporidae. 



Onchoporoides Ortmann, 1890. Family Onchoporidae. 



Onychocella Jullien, 1881. Family Opesiulidae. 



Oochilina Norman, 1903. Synonym of Crassimarginatella. 



Opisthornithopora Lang, 1916. Family Pelmatoporidae. Cretaceous cribri- 

 morph. 



Orbitulipora Stoliczka, 1861. Family Orbituliporidae. 



Ornatella Canu, 1900. Genotype Membranipora ornata D'Orbigny, 1850. Cre- 

 taceous. Incompletely studied. 



Omithopora D'Orbigny, 1852. Synonym of Bugula. 



Ornithoporina D'Orbigny, 1852. Synonym of Bugula. 



Orthopora Waters, 1904. See Orthoporidra, new name. 



Orthoporidra, new name. Proposed for Orthopora Waters, 1904 (not Hall, 

 1886). Family Lekythoporidae. 



Osthimosia Jullien, 1888. Family Celleporidae. 



Otionella Canu and Bassler, 1917. Family Biflustridae. 



Otopora Lang, 1916. Family Otoporidae. Cretaceous cribrimorph. 



Ovaticella Maplestone, 1900. Type O. turbinata Maplestone, 1900. Tertiary of 

 Australia. Type incomplete. Synonym or close to Adeonellopsis. 



Pachydera Marsson, 1887. Pal. Abh., vol. 4, p. 100. Type and only species, 

 P. grandis Marsson. Costulae. Referred by Lang to Pelmatoporidae. 



Pachykraspedon Koschiusky, 1885. First species, P. clarum Koschinsky, 1885. 

 Palaeontographiea, vol 32, 1885, p. 43. ?Synonym for Mastigophora. 



Pachystomaria MacGillivray, 1895. Family Galeopsidae. 



