476 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



Hippaliosina inarmata new species 

 Plate 56, fig. 10 



Zoarium encrusting on shells and corallines. Zooecia of moderate 

 size; 0.45 to 0.55 mm long by 0.35 to 0.40 mm wide, distinct with a 

 raised separating line; front little inflated, a granular pleurocyst with 

 a row of large areolae which are separated by short ribs, without umbo 

 or other irregularities. The aperture measures about 0.13 mm in either 

 dimension, rounded distally, the poster broader than the anter; the 

 proximal border nearly straight; cardelles wanting. The operculum has 

 the form of the aperture, the distal border thickened and a narrow 

 sclerite on either side close to the lateral edge, as in H. rostrigera. The 

 peristome is thin, slightly raised all around the aperture and with a 

 low lappet on each side, the primary aperture not obscured. There are 

 no avicularia, no spines, no dietellae. 



The ovicell is endozooecial, but its porous frontal surface is partially 

 exposed, scarcely raised above the level of the aperture. 



The species is readily distinguished from H. rostrigera by the shorter 

 aperture which is widest proximally, by the complete peristome and by 

 the entire absence of avicularia. 



Type, AH F no. 104. 



Type locality: Hancock Station 136-34, Clarion Island west of 

 Mexico, 18°20'05"N, 114°44'40''W, 32 fms. Also at Station 136-34 

 in the same region, 57 fms; 239-34, Port Utria, Colombia, shore; and 

 Albatross Station 2886, ofif the Oregon coast, 43°59'00''N, 124°56' 

 30"W, at 50 fms. 



Hippaliosina costifera new species 

 Plate 56, figs. 11-12 



Zoaria encrusting on the smooth surface of pebbles, sometimes multi- 

 laminar, white. Zooecia moderate in size, 0.55 to 0.75 mm long by 0.35 

 to 0.50 mm wide; distinct, the younger ones separated by deep grooves. 

 The frontal is thick pleurocyst with a marginal row of large areolar 

 pores, between which strong costal ridges extend radially toward an 

 irregularly broad, prominent umbo. Frequently the marginal areolae 

 extend around the distal end in front of the aperture and in older zooecia 

 the rows of pores mark the outlines. The primary aperture is slightly 

 elongate, 0.14 mm long by 0.12 mm wide, semielliptical, the condyles 

 small and set far back, the proximal border nearly straight and extending 



