ROTALIIDAE — DISCORBIS. 39 



Numerous specimens are here referred to Terquem's species, 

 although they probably belong to perhaps more than one species, 

 and it is doubtful if any of them are identical with that of Terquem. 

 They are probably more nearly related to such forms as occur in 

 the shallow Indo-Pacific region than to that of the European coast. 



Discorbis mira, new species. 



(Plate 6, Figures 10, 11.) 



Discorbina turbo H. B. Brady (and subsequent authors; not d'Orbigny), Rep. Voy. Chal- 

 lenger, Zoology, vol. 9, 1884, p. 642, pi. 87, figs. 8 o to c. 



Test planoconvex, dorsal side forming a low cone, ventral side flattened 

 and very slightly convex, trochoid, the last-formed chamber consisting of 

 about 6 chambers; sutures oblique, curved very slightly, if at all, depressed 

 on the dorsal side, on the ventral side depressed, the area thus formed often 

 filled by alar prolongations from the center; periphery slightly lobulate, 

 on the dorsal side the sutures often slightly limbate; the walls coarsely 

 punctate, on the dorsal side irregularly so, the punctae near the outer margin 

 of the chamber, less frequent elsewhere; aperture an elongate, slightly arched 

 slit at the inferior margin of the chamber; color white. 



Diameter up to 0.65 mm. 



Specimens of this species have been fairly common in the region, 

 occurring at most of the stations, often in considerable numbers, 

 the specimens agreeing very closely with the figures given by Brady 

 in the Challenger report. A comparison of these figures, however, 

 with the Modele of d'Orbigny and the subsequent figure given by 

 Fornasini, will show that the Rotalia {Trochulina) turbo of d'Orbigny 

 is a very different species from that figured by Brady and which I 

 have figured here. D'Orbigny's specimens were found fossil in the 

 Paris Basin. From the abundance of this species in the Tortugas 

 region it is probable that it is widely distributed, both here and in 

 the tropical Pacific. 



In spite of the considerable number of specimens, the character- 

 istics of the species are very closely held and very little variation is 

 shown. 



Discorbis floridana, new species. 

 (Plate 5, Figures 11, 12.) 



Test rotaliform, periphery slightly, if at all, lobulated, dorsal side rounded, 

 much convex, ventral side concave, somewhat umbilicate; chambers com- 

 paratively few, 5 or 6 in the last-formed coil, on the dorsal side coarsely 

 punctate, on the ventral side punctate near the periphery, but on the inner 

 concave portion smooth, with very fine punctse, if any; sutures in the younger 

 portion slightly limbate, those of the later portion not limbate, rather in- 

 distinct, very slightly depressed; aperture an elongate, arched opening at 

 the base of the last-formed chamber, opening on the umbilicate area, often 

 with a sHght, thin Hp; color of the early whorls brown, of the last whorl white. 



Diameter not exceeding 0.4 mm. 



These specimens, which occurred in considerable numbers at 

 several stations, do not seem to fit any of the described species. 



