112 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



Occurrence. — 



D. 5574. Simaluc Island, north of Tawi Tawi; 5° 40' 45" N.; 



120° 07' 57" E.; 340 fathoms. 

 D. 5579. Sibutu Island, Darval Bay, Borneo; 4° 54' 15" N.; 

 119° 09' 52" E.; 175 fathoms; fne. S., Co. 

 Cotypes.— Cat. Nos. 7906, 7907, U.S.N.M. 



Family HIANTOPORIDAE MacGillivray, 1895 



The larva of this family is not known. The species which it con- 

 tains were classified in the Beaniidae by Kirkpatrick in 1890 and in 

 the Bicellariidae by Levinsen in 1909. As they form a group rather 

 distinct from the Membraniporae we have adopted MacGillivray 's 

 solution of the matter. The known genera are : Tremopora Ortmann, 

 1890, Hiantopora MacGillivray, 1886, Tremogasterina Canu, 1911 

 and Hoplocheilina Canu, 1911. Levinsen unites Tremopora and 

 Hiantopora in a single genus, but we maintain both genera because 

 it appears that the function of the opercular valve is not identical in 

 the two. Hoplocheilina Canu, 1911 which we described and illus- 

 trated in 1920, we now refer to this family. 



Genus TREMOPORA Ortmann, 1890 



Tremopora Canu and Bassler, North American Early Tertiary Bryozoa, Bull. 

 106, U. S. National Museum, p. 139, fig. 33. 



The opercular valve always closes the ovicell. The mural rim 

 bears one or two large bifurcated oral spines and an avicularium 

 more or less developed. 



Genotype. — Tremopora dendracaniha Ortmann, 1890. 



Range. — Miocene (Helvetian) — Recent. 



TREMOPORA RADICIFERA, Hincks 1881 



Plate 11, figs. 2-6 



1889. Membranipora radicifera Jelly, Synonymic Catalogue of Marine Bryozoa, 



p. 162 (bibliography). 



1890. Membranipora radicifera Kirkpatrick, Hydroida and Polyzoa Torres 



Strait, Proceedings Royal Society Dublin, vol. 6, p. 616, pi. 16, fig. 1. 

 1909. Hiantopora radicifera Levinsen, Morphologic studies on the cheilostoma- 



tous Bryozoa, p. Ill, pi. 4, fig. 6. 

 1926. Hiantopora radicifera Harmer, Polyzoa Siboga Expedition, p. 256, pi. 34, 



fig. 4 (bibliography). 



Measurements. — 



^ • \ho = 0.45 mm. 7 • (is = 0.60-0.65 mm. 



Opesium^, Zooecia^ „ .: 



1 Uo = 0.25mm. . lZ2 = 0.40 mm. 



This species is quite polymorphic. We recognize (1) the typical 



form, (2) the variety separata with separated cells, both fossil and 



recent, (3) the variety bifoliata formed of two lamellae back to back 



