658 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 51. 



Diameter, up to 3 mm. ; usually less. 



Type-specimen.— (Csit. No. 9127, U.S.N.M.) imm Alhatross 1)5388, 

 in 226 fathoms, between Burias and Luzon, Philippines. 



CRISTELLAKIA EXPANSA, new species. 



Test biconvex, with a very wide, prominent, very thin keel, cham- 

 bers with a large alar projection on the umbiUcal end extending be- 

 yond the umbilicus and onto the previous whorl; sutures with raised 

 ribs ending in a knob near the umbilicus, remainder of the surface 

 smooth; aperture radiate, apertural face concave. 



Diameter, up to 3 mm. 



Type-specimen.— (Csii. No. 9128, U.S.N.M) from ^Z&a^ross station 

 D5467, in 480 fathoms, east coast of Luzon. 



CRISTELLAKIA EXPANSA, new species, var. PLANULATA, new variety. 



Variety differmg from the t}T)ical mainly in the lack of ornamenta- 

 tion characteristic of the type, and, if at all ornamented, consistmgof 

 indistinct costae in the axis of growth; alar projections more dis- 

 tinct than in the type, due to the lack of ornamentation hiding the 

 sutures, usually more compressed than in the typical. 



Type-specimen.— {C&t. No. 9129, U.S.N.M.) from Albatross D5220, 

 in 50 fathoms, between Marin duque and Luzon, Phihppines. 



CRISTELLAKIA COSTATA (Fichtel and MoU), var. MULTICOSTA, new variety. 



Variety very much compressed, camplanate, with the costse along 

 the limbate sutures obsolete ; the sutures lightly depressed ; the orna- 

 mentation of each chamber consisting of a large number of fine raised 

 costse spreading fan-like from the aperture as a center backward, 

 and covermg the entire surface of the chamber; aperture radiate, 

 protruded. 



Diameter, up to 4 mm. 



Type-specimen.— {C&t. No. 9130, U.S.N.M.) from Albatross D5538, 

 in 256 fathoms, between Negros and Siquijor, Philippines. 



CRISTELLARU COSTATA (Ficlitel and MoU), var. SUBDECORATA, new variety. 



Variety with the costse of the sutures the predominant factor in 

 the ornamentation, the areas between with fine costsB or striae, an- 

 astomosing; the costae of the sutures large and well marked, sharply 

 raised above the surface of the test; the umbihcal region covered 

 with a thick cluster of irregular bosses; periphery with traces of a 

 keel between the sutures. 



Diameter, up to 4 mm. 



Type-specimen.— (Cat. No. 9131, U.S.N.M.) from Albatross 1)5^54, 

 in 153 fathoms, east coast of Luzon. 



