172 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



CELLARIA GRANULATA, new species 



Plate 21, figs. 4-6 



Description. — The zoarium is free and articulated; the segments 

 of 1 centimeter in length are thin, cylindrical, narrower at the base, 

 and inflated at the level of the ovicelled zooecia. The zooecia are 

 distinct, separated by a minute furrow, elliptical, elongated, arranged 

 in quincunx; the mural rim is thin, salient, granulated; the cryptocyst 

 is rather deep, concave, granulated proximally. The apertura is 

 large, semilunar, surrounded by a thin, granulated peristome; the 

 proximal border bears laterally two small indentations and some- 

 times two minute denticles. The ovicell is endotoichal, large, 

 covered over by a lamella, convex and transverse; its orifice is very 

 large and oblique on the plane of the aperture. The avicularium is 

 lozenge shaped, almost as large as a zooecium; its opesium is elliptical 

 and median. The ovicelled zooecia are broader, grouped on a 

 swollen portion of the segment. 



Structure. — The orifice of the ovicell is orbicular and normally 

 placed above the aperture and in the same plane, but it is frequently 

 covered and protected by a convex, fragile, lamella rising from the 

 cryptocyst of the distal zooecium. This arrangement gives to some 

 ovicells the aspect of Stomhypselosaria. Lifting the convex lamella 

 with the scalpel, shows immediately the normal orifice, so that the 

 resemblance is only a false appearance. Harmer, 1926, has noted 

 the same structure in Cellaria tecta. It is clearly visible on our 

 photographs. The granules and especialy the proximal denticles 

 of the aperture disappear rapidly at the least weathering. 



Measurements . — 



[7m = 0.14mm. „ . lLz = 0.Q0 mm. 



Aperturai-, „ , . Zooecia), A .„ _ 



K Ua = 0.14mm. Hz = 0.40 mm. 



Affinities. — In its avicularium, this species much resembles Cel- 

 laria contigua MacGillivray, 1895, but differs from it in its convex 

 ovicell and its wide ovicelled zooecia. It differs from Cellaria tecta 

 Harmer, 1926, in its more elongated cells, its regularly concave 

 cryptocyst, and its larger opesium of the avicularium. All of our 

 specimens were dead and deprived of their chitinous appendages; 

 they did not live where they were dredged. The Cellariidae are 

 commensals on the large floating algae. 

 Occurrence. — 



D. 5574. Simaluc Island, north of TawiTawi; 5°30'45" N.; 120° 



07' 57" E.; 340 fathoms. 

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

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

 Cotypes.— Cat. Nos. 7979, 7980, U.S.N.M. 



