158 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Clavulino rotundata- — Moterial examined. 



CLAVULINA PRIMAEVA Cnshman. 



Plate 30, figs. 2a, h, 3, 5-7. 



Clavulino. primaeva Cushman, Proc. U. S. Nat. llus., vol. 44, 1913, p. 635, pi. 80, 

 figs. 4, 5. 



Descriptio7i. — ^Test elongate, cylindrical, slender, composed of 

 numerous chambers; early portion triserial, median portion biserial, 

 terminal portion uniserial; chambers high; wall thick, light gray in 

 color, smooth, sutures slightly depressed; aperture small, with a 

 slight neck, more marked in the young stages. 



Length about 3 mm. 



Type specimen. — (Cat. No. 8507, U.S.N.M.) from Albatross station 

 D5585, vicinity of Sibuko Bay, Borneo, 476 fathoms (871 meters). 



This species is peculiar in the retarded taking on of the typical 

 uniserial character of chamber arrangement and in the length of 

 time that the biserial conditionis held. In this it is distinctly primi- 

 tive, much more so than in any other known species. The early 

 triserial condition, on the other hand, is not much longer held than 

 in some other species of the genus. The figure of a young specimen 

 shows the typical clavuline neck even while the biserial condition is 

 still held. 



The species also occurred at D5526, between Siquijor and Bohol 

 Islands, in 805 fathoms (1,472 meters). 



Clavuhna primaeva — Material examined. 



