NO. 1 OSBURN : EASTERN PACIFIC BRYOZOA — CHEILOSTOMATA 47 



spines but these are usually wanting. The characters therefore are those 

 of a simple membranipore except for the endozooecial ovicell. Genotype, 

 Aplousina gigantea Canu and Bassler, 1927. 



^^., Aplousina filum (Jullien), 1903 

 ^ ' Plate 4, fig. 1 



Membranipora filum Jullien, 1903 :41 



Biflustra lacroixii, Smitt, 1873 : 18. 



Aplousina filum, Canu and Bassler, 1930:5 (synonymy). 



Zoarium encrusting shells. The zooecia are distinct, rounded, ovate 

 or elliptical ; varying greatly in their dimensions, ranging in lengths from 

 0.60 to 0.80 mm and in width from 0.40 to 0.55 mm, shorter zooecia 

 usually being wider. The walls are thin, the cryptocyst usually a mere 

 granulated border but sometimes a little broader proximally ; gymnocyst 

 small or wanting ; the opesia occupying nearly all of the front. A minute 

 pointed spine is rarely present on the mural rim at each side of the 

 operculum. No avicularia. 



The ovicell is endozooecial but prominent, lunate, the aperture wide 

 and closed by a special membrane; about 0.25 mm wide by 0.14 mm long, 

 very finely granulated. 



Known from the eastern Atlantic region, from the Gulf of Mexico 

 {Biflustra lacroixii, Smitt, non Audouin), and from the Galapagos Is- 

 lands, Albatross Sta. D. 2813 (Canu and Bassler). 



Hancock Stations: 557-36, Isla Partida and 267, San Esteban Is- 

 land, Gulf of California; 328, Cocos Island, Costa Rica; 431-35, Oc- 

 tavia Rocks, Colombia; 155-34, Albemarle Island and 788-38, Daphne 

 Major Island, Galapagos; 14 to 60 fms. 



,f.^ Aplousina major new species 

 Plate 4, fig. 2 



The zoarium forms a thin yellowish or brownish crust on shells. Zo- 

 oecia very large, averaging in length about 0.90 mm (range 0.80 to 1.20 

 mm) and in width about 0.70 mm. There is great variation in the shape, 

 as wide as long to twice as long as wide. A narrow brown line separates 

 the mural rims which are thin and beaded all around the border except 

 that the distal rim is sometimes smooth. The opesia occupies all of the 

 front ; gymnocyst wanting ; cryptocyst narrow, descending sharply, often 

 scarcely evident. The chitinous ectocyst is unusually thick, yellow to 

 brownish in color; the operculum very large (0.25 mm wide), thicker 



