8 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 75 



Genus BOLIVINA d'Orbigny, 1839 



BOLIVINA COSTATA d'Orbigny 



Plate 3, figures 9 a-c 



Bolivina costata d'Orbigny, Voy. Am6r. Merid., 1839, vol. 5, pt. 5, "Foraminif^res," 

 p. 62, pi. 8, figs. 8, 9. 



Test small, tapering, broadest toward the apertiiral end in both 

 front and side views, periphery broadly rounded ; chambers numerous, 

 the earlier ones low and broad, later ones becoming gradually higher 

 until in the last-formed ones the height is often nearly equal to the 

 breadth, slightly inflated; sutures somewhat indistinct, but appearing 

 as irregular angular lines between the sutures pointing toward the 

 aperture, due to the suture line extending out onto the costae and 

 backward at the same time; wall very coarsely perforate, with a few 

 sharp, raised longitudinal costae continuous over the sutures, usually 

 five or six costae on a side, last-formed chambers of each series usually 

 smooth on the outer face; aperture narrow, elliptical, extending in 

 from the base nearly in the median line. 



Maximum length, 0.40 mm.; breadth, 0.15 mm.; thickness, 

 0.12 mm. 



D'Orbigny's types are from Cobija, Chile, in d'Orbigny's time 

 Bolivian territory. In our material, the species has proved to be 

 very abundant at Eten, less so at Pimentel, and rather scarce at 

 Payta, Peru. It did not occur in the material from Chile or Ecuador. 

 It is by far the dominant species at Eten, occurring by hundreds and 

 showing very little variation. It is identical with d'Orbigny's figure 

 and description, but not at all the same as Bolivina costata of Brady 

 in the Challenger report. 



BOLIVINA DONIEZI Cushman and Wickenden 



Plate 3, figures S a, b 



Bolivina doniezi CvBHUAN and Wickenden, Proc. U. S. Nat. Mus., vol. 75, 1929, 

 p. 9, pi. 4, figs. 3 a, b. 



Test small, depressed, broadest near the apertural end; chambers 

 comparatively few, consisting of eight or ten pairs; wall very coarsely 

 perforate, the earlier chambers with a few coarse perforations near 

 the basal margin, the adult chambers with the coarse perforations 

 scattered over the general surface; chambers fairly narrow, but 

 becoming higher toward the apertural end; sutures distinct, depressed, 

 strongly oblique; aperture elongate, arched, in the median line at the 

 base of the last-formed chamber. 



Length of figured specimen, 0.21 mm.; breadth, 0.10 mm.; thick- 

 ness, 0.7 mm. 



This species described from Juan Fernandez is very rare at Payta, 

 Peru. Its characters hold very distinctly. 



