40 SHALLOW-WATER FORAMINIFERA OF TORTUGAS REOION. 



They have a beautiful brown color, the wall translucent, and on 

 the ventral side especially have a peculiar appearance, due to the 

 lack of the punctfE in the umbilical area. There is some slight 

 variation, as shown in the figures (plate 5, figs. 11, 12), but all have 

 the characteristic color and general appearance from both the 

 dorsal and ventral sides. 



Discorbis advena, new species. 



Discorbina rosacea H. B. Brady (in part) (not d'Orbigny), Rep. Voy. Challenoer, Zoology, 

 vol. 9. 1884. p. 644, pi. 87. fig. 1.— Flint, Rep. U. S. Nat. Mua.. 1897 (1899). p. 

 327, pi. 72. fig. 3 ?. 



Test rotaliform, dorsally convex, ventrally concave, composed of numer- 

 ous chambers, usually 6 in the last-formed coil, distinct, the periphery rounded 

 in the final chambers, earlier development with a rather acute edge; sutures 

 distinct, very slightly depressed, oblique; wall fine, translucent, very finely 

 punctate; on the ventral side the test is umbihcate, the chambers ending in 

 a peculiar inflated point; aperture a very narrow, slightly curved opening at 

 the base of the inner margin of the last-formed chamber. 



Diameter up to 0.5 mm. 



This is one of the most common species of this genus in the col- 

 lection, occurring at more than half the stations. It is very close 

 to the figure given by Brady, referred to Discorbina rosacea d'Orbigny. 

 A comparison of this with d'Orbigny 's original Modele, however, 

 shows little in common between the two. The figures given by 

 Flint may possibly be this species also. This is very different from 

 the figures given by Brady as Discorbina rosacea (plate 87, fig. 4). 

 The species does not seem to have been definitely described and 

 figured, and I have here given it a new name in order that it may be 

 distinguished, if, as is probable, this distribution may be fairly 

 wide in the warm waters of this general region in the Atlantic. Spec- 

 imens in the Tortugas collection showed very little variation, and 

 the species has been a very clear-cut one at all the stations where 

 it occurred. 



Discorbis auberii (d'Orbigny). 



Rosalina auberii d'Orbigny, in De la Sagra, Hist. Fis. Pol. Nat. Cuba, 1839, "Forami- 

 nifhrea," p. 94, pi. 4, figs. 5 to 8.— Cushman, Proc. U. S. Nat. Mua., vol. 59. 1921, 

 p. 59. pi. 14, figs. 1 to 3. 



Test rotaliform, with a low spire; periphery carinate, acute, the ventral 

 side shghtly, if at all, convex; composed of several coils with 4 chambers in 

 each; sutures distinct, somewhat depressed, oblique on the dorsal side, nearly 

 radiate on the ventral; wall rather coarsely perforate; aperture at the base 

 of the last-formed chamber, a curved, narrow slit. 



Diameter of the Tortugas specimens 0.40 mm. 



D'Orbigny described this species from Cuba and Martinique, and 

 I have recorded it from the north coast of Jamaica. The only 

 station in the Tortugas collection at which it has occurred is station 

 10, where it is rare. 



