100 
BULLETIN 125, UNITED STATES NATIONAL MUSEUM. 
Paleontological bibliography. 
1842. Eschara biaperta Michelin, Iconographie zoophytologique, p. 330, pi. 79, fig. 3. 
1859. Lepralia biaperta Busk, Monograpli Fossil Polyzoa of the Crag, Publications Paleontographical 
Society, London, vol. 14, p. 47, pi. 7, fig. 5. 
1862. Reptescharellina comuta Gabb and Horn, Monograph Polyzoa Secondary and Tertiary for¬ 
mations of North America, Journal Academy Natural Sciences of Philadelphia, ser. 2, 
vol. 5, p. 147, pi. 20, fig. 31. 
1875. Lepralia biaperta Manzoni, I Briozoi del pliocene antico di Castrocaro, p. 21, pi. 2, fig. 28. 
1878. Lepralia biaperta Waters, Bryozoa (Polyzoa) from the Pliocene of Bruccoli (Sicily), Transac¬ 
tions Manchester Geological Society, vol. 14, p. 13, fig. 8. 
1879. Lepralia biaperta Seguenza, Le formazioni terziarie nella Provincia di Reggio (Calabria), 
Reale Accademia dei Lincei, Memorie della Classe di Scienze Fisiche, Matematiche e 
Naturali, ser. 3, vol. 6, pp. 81, 202. 
1887. Lepralia biaperta Waters, On Tertiary Bryozoa from New Zealand, Quarterly Journal Geo¬ 
logical Society, London, vol. 43, p. 65. 
1895. Schizoporella biaperta MacGillivray, Monograph Tertiary Polyzoa of Victoria, Transactions 
Royal Society of Victoria, vol. 4, p. 85, pi. 11, fig. 20. 
1895. Schizoporella biaperta Neviani, Briozoi fossili della Farnesina e Monte Mario presso Roma, 
Paleontographica Italica, vol. 1, p. 110 (sep. 34). 
1896. Schizoporella biaperta Neviani, Briozoi Postpliocenici di Spilinga (Calabria), Atti Accademia 
Gioenia di Scienze Naturali in Catania, ser. 4, vol. 9, p. 33, fig. 16. 
1896-1898. Schizoporella biaperta Neviani, Briozoi neozoici di alcune localita d’Italia, Bollettino 
della Societa Romana per gli Studi Zoologica, pt. 3, p. Ill (sep. 10); pt. 5, pp. 4, 7. 
1897. Schizoporella biaperta Neviani, Corallari e Briozoi neogenici di Sardigna, Bolletino della 
Societa Geologica Italiana, vol. 15, p. 588 (sep. 20). 
1901. Schizoporella biaperta Neviani, Briozoi neogenici della Calabrie Paleontographia Italiana, 
vol. 6, p. 195 (sep. 8) (regional bibliography). 
1905. Schizoporella biaperta Neviani, Briozoi fossili di Carrubare (Calabria), Bollettino Societa 
Geologica Italiana, vol. 23, p. 532 (sep. 30). 
1919. Stephanosella biaperta Canu and Bassler, Geology and Paleontology of the West Indies, 
Paleontology, Publications Carnegie Institution of Washington, no. 292, p. 91, pt. 1, 
figs. 16-18. 
1920. Stephanosella biaperta Canu and Bassler, North American Early Tertiary Bryozoa, Bull 
106, U. S. National Museum, p. 344. 
nr . . k = 0.10 mm. 
Measurements .—Apertura 7 . 
r la =0.10-0.12 mm, 
Zooecia 
[£2 = 0.40 mm. 
lz = 0.30 mm. 
Variations .—^This species is quite variable in its external aspects and in its 
micrometric measurements. The ovicelled zooecia are oriented in all directions; 
this absolutely inexplicable phenomenon characterizes this species and contributes 
much to making it often absolutely unrecognizable. 
We give figures of specimens chosen from different formations which will suffice 
to enable the reader to avoid errors of determination. The specimens with large 
tremopores should possibly be separated as a variety, in which case Gabb and 
Horn’s name of comuta would be available. This is one of the few species common 
to both the Atlantic and Pacific. 
Occurrence .—Miocene (Bowden marl): Bowden, Jamaica (rare). Miocene 
(Duplin marl): Wilmington, North Carolina (rare). Pleistocene: Los Angeles 
(rare). Dead Mans Island off San Pedro (very rare), and Santa Monica, California 
(rare); Vero, Florida (rare). 
Geological distribution .—Miocene of Australia (MacGillivray); Helvetian of 
France (Michelin), of Sardinia (Neviani), and Italy (Seguenza); Zanclean of Italy 
(Seguenza, DeStefani); Sahelian of Oran (Collection Canu); Plaisancian of England 
