50 BULLETIN 104, UNITED STATES NATIONAL MUSEUM. 



perforate, smooth or ornamented; aperture distinctive, an arched 

 opening with a vertical notch or slit in the middle of the lower edge> 

 usually with tooth-like projections upward at either side. 



This genus is almost entirely confined to the Pacific and Indian 

 oceans. There are records of its occurrence as far back as the Creta- 

 ceous, but Tertiary records seem to be very rare. 



PLEUROSTOMELLA SUBNODOSA (Reuss). 



N'odosaria nodosa Reuss (part), Yerst. Bohm. Kreid., pt. 1, 1845, p. 28, pi. ^'^, 



fig. 22. 

 Dentalina subnodosn Reuss (part), TIaidinger's Nat. Abhandl., vol. 4, 1850, p. 24, 



pi. 1, lig. 9. 

 Pleurostomella subnodosa Reuss, Sitz. Akad. Wiss., Wien vol. 40, 18G0, p. 204, 



pi. 8, fig. 2a, b.—U. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 



412, pi. 52, figs. 12, ]3.— Pearcey, Trans. Hist. Nat. Soc. Glasgow, vol. 2, 1890, 



p. 177. — Chapman, Proc. Zool. Soc. London, 1895, p. 25; Joiim. Linn. Sor. 



London, vol. 30, 1910, p. 405.— Cushman, Bull. 71, U. S. Nat. Mus., pt. 2, 



1911, p. 51, figs. 82a-c (in text); Bull. 100, U. S. Nat. Mus., vol. 4, 1921, p. 139. 



Description. — 'Test much elongate, very slightly compressed, nearly 

 cylindrical, hardly tapering, the apical end broadly rounded, the 

 apertural end subacute in front view, rounded in side view; chambers 

 several, the very early ones biserial, the later uniserial, but with 

 oblique sutures showing the traces of the biserial condition; aperture 

 fairly broad; sinus broad with slight projections at each side; color 

 white. 



Length 0.65-0.90 mm. 



Distribution. — In the Challenger Report Brady notes the appear- 

 ance of this species in the South Atlantic in deep water, 2,200 and 

 2,350 fathoms (4,024 and 4,298 meters). Pearcey records it from the 

 warm area of the Faroe Channel as very rare. I have not seen the 

 species in any of the material I have examined from the Atlantic. It 

 seems to be open to question whether or not this recent species from 

 deep water is the same as that described by Reuss from the Creta- 

 ceous, but I have had no specimens to determine this. 



pleurostomella acuminata, new specIeB. 



Plate 19, fig. 6. 



Pleurostomella alter nans H. B. Brady (part) (not Sch wager), Rep. Voy. Challmger, 

 Zoology, vol. 9, 1884, p. 412, pi. 51, fig. 22 (not fig. 23). 



Description. — Test elongate, subcylindrical or fusiform, the initial 

 end pointed and terminating in a definite spine; apertural end in 

 front view broadly rounded, in side view acute and tapering; cham- 

 bers of the early portion crowded, later ones much less so, biserial, 

 inflated; sutures, distinct, slightly depressed; wall smooth, finely 

 punctate; aperture narrow, vertical, with an upwardly projecting 



