10 PROCEEDINGS OF THE NATIONAL MUSEUM vol.75 



Length, 0.30-0.35 mm.; breadth, 0.20-0.22 mm.; thickness, 0.10- 

 0.12 mm. 



Holotype. —{Cat. No. 20786, U.S.N.M.) From off Lota, Chile. 



At the type locahty the specimens show a considerable range of 

 variation. The spire may become somewhat higher and the whole 

 test slightly more rounded. The amount of limbation of the sutures 

 may be greater in the earlier coils and slightly less than shown in the 

 adult. The test has a peculiar silvery- white, opaque appearance in 

 all specimens seen. There is a single specimen from Eten, Peru, 

 that is probably the same. 



DISCORBIS CONSOBRINA (d'Orbigny) 



Plate 4, figures 1, 2 



Rosalina consobrina d'Orbigny, Voy. Am^r. Merid., 1839, vol. 5, pt. 5, " Foram- 

 iniferes," p. 46, pi. 7, figs. 4-6. 



Test biconvex, the dorsal side more strongly so, ventral side 

 depressed in the umbilical region, periphery rounded; chambers five 

 to seven in the last-formed whorl, distinct, regularly increasing in 

 size as added, slightly inflated, on the ventral side ending in distinct 

 angles on the umbilical end; sutures distinct, on the dorsal side 

 oblique, very slightly curved, very little if at all depressed, on the 

 ventral side slightly curved, nearly radial, depressed; wall smooth, 

 distinctly perforate; aperture below the distinct lip on the ventral 

 side of the chamber and extending into the umbilical region. 



Diameter, 0.30 mm.; height, 0.22 mm. 



D'Orbigny described this species from off the coast of Peru, and 

 it has occurred in our material from off Payta and Eten, Peru, 

 and Corral, Chile. Plate 4, figure 1 shows the microspheric form 

 which has many more chambers and more coils and a higher spire 

 than in the megalospheric form (fig. 2). D'Orbigny 's figured speci- 

 men was evidently a megalospheric one. A comparison of figure 2 

 with d'Orbigny's type figure will show the very close similarity of 

 the two. 



Genus EPONIDES Montfort, 1808 



EPONmES PERUVIANA (d'Orbigny) 



Plate 4, figures 5 a-c 



Rosalina peruviana d'Orbigny, Voy. Amer. M6rid., 1839, vol. 5, pt. 5, "Foram- 

 inif^res," p. 35, pi. 2, figs. 3-5. 



Test trochoid, nearly equally biconvex, periphery carinate, generally 

 circular in outline; chambers numerous, distinct, about eight in the 

 last-formed whorl, on the dorsal side forming a very even polished 

 surface, ventrally inflated, giving a very distinct appearance to the 

 test; sutures very distinct on the dorsal side, curved, flush with 



