ART. 13 BRYOZOAN FAUNA CANU AND BASSLER 6 



There are areal spicules but no serrate denticles, while in the Philip- 

 pine and in the Gulf of Mexico specimens there are no spicules. 



Biology. — The discovery of this equatorial species at the Galapagos 

 confirms our preceding deductions on the recent formation of the 

 Isthmus of Panama, in which we have discovered it with certainty as 

 a fossil. Its geographic extension is very great, but everywhere it 

 lives only in waters of little depth. Its presence in the fossils always 

 reveals the vicinity of the shore. It is able to cross the great depths 

 of the ocean only when parasitic on floating algae. 



Occu7Tence. — Galapagos Islands, D. 2813. 



Geographic distribution. — Atlantic: Gulf of Mexico and Florida 

 (29 fathoms) ; Tortugas (10 fathoms) and between Florida and New 

 Orleans (27-30 fathoms) . Pacific : Sulu Sea and Celebes Sea in the 

 Philippines (20^24 fathoms) ; Samboangan (10 fathoms) ; Australia, 

 Queensland and Victoria, Palm Island (8-10 fathoms), and Darnley 

 Island in Torres Strait. Indian Ocean : Zanzibar (8-10 fathoms) : 

 Sudanese Ked Sea (.5-30 fathoms) and Ceylon. 



Plesiotypes.—Cfii. No. 8469, U.S.N.M. 



Family HINCKSINIDAE Canu and Bassler, 1927 

 Genus APLOUSINA Canu and Bassler, 1927 



APLOUSINA FILUM JuIIien. 1903 

 Plate 1, Figures 1, 2 



1873. Biflustra lacroixii Smith (not Audouin), Floridan Bryozon, p. 18, yl. 4, 

 figs. 85 to 88 (Florida, 21-97 m.). 



1902. Membranipora reticulum Calvet (not Linnaeus), Bryozoaires marines 



des Cotes de Corse, Travaux de I'lnstitut Zoologique de Montpellier, 

 ser. 2, mem. 12, p. 14. 



1903. Membranipora filum .Tullien, Bryozoaires provenant des campagnes de 



I'Hirondelle 1886-1888, Resultats des campagnes scientiflques accom- 

 panies par le Prince de Monaco, fasc. 23, p. 41, pi. 5, fig. 4 (Azores, 

 130-318 m.). 



1907. Membranipora filum Cata'et, Bryozoaires des expeditions scientifique du 

 Travailleur et du Taliaman, VIII, p. 386 (bibliography). (Cape Verde 

 Islands, 80-180 m. ; Cape Spartel, northwest of Morocco, 717 m.) 



1923. Callopora filum Canu and Bassler, North American Later Tertiary and 



Quaternary Bryozoa, Bulletin 125, U. S. National Museum, p. 42, pi. 



45, fig. 5 (Pleistocene of Mount Hope, Panama). 



V189S. Membranipora capriensis Waters, Observations on Membraniporidae, 



Linnean Society's Journal, Zoology, p. 690, pi. 47, fig. 6 (Capri, Italy). 



Structure. — In 1923 we interpreted badly the description of the 

 ovicell given by Calvet in 1907 without figures. As it is easy to see 

 on the figure of Smitt, 1873, the ovicell is really endozooecial ; it is 

 often ornamented with a small frontal cicatrix. 



The opercular valve is very short and is supported on the mural 

 rim, with a width of 0.16-0.20 mm. Smitt said also that it is small, 



