154 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Genus CLAVULINA d'Orbigny, 1826. 



CL.\VULINA COMMUNIS d'Orbigny. 



Plate 31, fig. 1. 



Clavulina comviunis d'Orbigny, Ami. Sci. Nat., vol. 7, 1826, p. 2G8; Foram. Foss. 



Vienne, 1846, p. 196, pi. 12, figs. 1, 2.— H. B. Brady, Rep. Voy. Challenger, 



Zoology, vol. 9, 1884, p. 394, pi. 48, figs. 1-13.— Cushman, Bull. 71, U. S. Nat. 



Mus., pt. 2, 1911, p. 72, figs. 115-117 (in text). 

 Verneuilina comviunis Jones and Parker, Quart. Joura. Geol. Soc, vol. 16, 18G0, 



p. 303. 



This species is common and rather widely distributed in the region. 

 The specimens vary in numerous details. The color of the wall varies 

 from a chalk}^ white to a dark gray, is usually smooth, and occasionally 

 somewhat roughened. Some of the specimens show excellently 

 the change from a triserial through the biserial to the final uniserial 

 arrangement of the chambers. Occasional specimens show well the 

 external tubular aperture. Although not definitely worked out 

 there seem to be indications of both microspheric and megalospheric 

 forms of the species in the material, from the comparative size of the 

 earlier chambers and the considerable difference in size of the adults. 



The species occurs at a large number of stations in the region vary- 

 ing in depth from 50 to 1,560 fathoms (91 to 2,853 meters), most of the 

 stations being in the neighborhood of 300 fathoms (549 meters), bot- 

 tom temperatures ranging from 38.2° to 76.3° F. (3.4° to 24.6° C), 

 and at the single shallow water station. 50 fathoms (91 meters), the 

 temperature was 76.3° F. (24.6° C). Specimens, however, were com- 

 mon at this last station. 



Clavulina communis — Material examined. 



