FORAMINIFERA OF THE PHILIPPINE AND ADJACENT SEAS. 379 



throughout, opaque; chambers 15 to 20 in the last-formed coil; 

 surface of the chambers smooth; sutures ornamented by a row of 

 raised tubercles, the sutures typical, nearly 

 straight, then near the periphery bend back 

 sharply to the outer edge. 



Diameter 3-5 mm. 



Distribution. — Type specimen (Cat. No. 

 15923, U.S.N.M.) from Albatross station 

 D5134, Sulu Archipelago, near Basilan 

 Island, 25 fathoms (46 meters). 



This is a common species in the Philippine 

 area, and while some of its specimens show re- 

 lations with other species it is usually distinct. 



At Albatross station D5428 there is a local 

 race, differing from the typical in the larger 

 size, and in the very prominent keel which in 

 the adult is thicker than that part of the test which is adjacent to it; 

 the rows of beads in the adult specimens usually become fused. 



OpereuUna pMlippinensis — Material examined. 



Fig. 15.— Operculina philip- 

 pinensis, new species. side 

 VIEW. X15. From station 

 D5134. 



OPERCULINA DISCOIDALIS (d'Orbigny). 



Assilina discoidalis v'ORBiQifY, Ann. Sci. Nat., vol. 7, 1826, p. 296, No. 1; Modules, 

 1826, No. 88.— FoRNAsiNi, Boll. Soc. Geol. Ital., vol. 22, 1903, pi. 14, fig. 8. 



Description. — Test close-coiled throughout; central portion with 

 a definite large proloculum, and the region next to it with numerous 

 large bosses; three or four coils, with numerous chambers, the center 

 part of each coil being thicker than the edges, leaving a deep-chan- 

 nelled spiral where the coils come together; the periphery with a 



