MILIOLIDAE—TRILOCULINA. 73 
Triloculina oblonga (Montagu). 
Vermiculum oblongum Montagu, Test Brit., 1803, p. 522, pl. 14, fig. 9. rn 
Triloculina oblonga d’Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 300, No. 16; ,Modéles, 1826, 
No. 95; in De la Sagra, Hist. Fis. Pol. Nat. Cuba, 1839, “‘ Foraminiféres,”’ p. 175, 
pl. 10, figs. 3 to 5.—Cushman, Proc. U. 8: Nat. Mus., vol. 59, 1921, p. 69, pl. 17, 
figs. 5, 6. 
Specimens which may be referred to this species are common at 
most of the stations in the collection, the most common form’ being 
similar to that figured by d’Orbigny in the Cuban monograph. I 
had specimens also from the north coast of Jamaica, and it seems 
to be common generally in the West Indian region, and also widely 
distributed elsewhere. 
Triloculina circularis Bornemann. 
Triloculina circularis Bornemann, Zeitschr. deutsch. geol. Ges., vol. 7, 1855, p. 349, pl. 19, 
fig. 4—Cushman, Bull. 71, U. S. Nat. Mus., pt. 6, 1917, p. 67, pl. 25, fig. 4; pl. 26, 
fig. 1; figs. 33, 34 (in text); Proc. U.S. Nat. Mus., vol. 59, 1921, p. 69. 
Miliolina circularis H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 169, pl. 4, 
figs. 3 atoc; pl. 5, figs. 13, 14? 
Triloculina circularis is one of the most common species of the 
genus in the collection. It is a species which is characteristic of 
just such conditions as obtained in the Tortugas region, and is 
widely distributed in shallow, tropical waters.. It is rather surprising 
that d’Orbigny did not describe it in his Cuban monograph, as it 
is widely distributed in the West Indian region. The developmental 
stages are interesting, but may always be distinguished by the large, 
flattened, semicircular tooth, which is usually placed somewhat out 
of the aperture itself. 
Triloculina rotunda d’Orbigny. 
Triloculina rotunda d’Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 299, No. 4.—Schlumberger, 
Mém. Soc. Zool. France, vol. 6, 1893, p. 206, pl. 1, figs. 48 to 50. 
Miliolina rotunda Millett, Journ. Roy. Micr. Soc., 1898, p. 267, pl. 5, figs. 15, 16.—Side- 
bottom, Manchester Lit. Philos. Soc., vol. 48, No. 5, 1904, p. 8. 
Test somewhat longer than wide; chambers rotund; periphery broadly 
rounded; surface of the test made up largely or entirely of the two last-formed 
chambers; sutures very slightly depressed; apertural end somewhat contracted, 
with a slightly thickened lip; aperture rounded, with a single bifid tooth, pro- 
jecting somewhat above the outline of the aperture; surface of the test smooth 
and shining, often with transverse wrinkles. 
Length of the Tortugas specimens up to 0.80 mm. 
D’Orbigny originally had 7’. rotunda from the Adriatic Sea, and 
Schlumberger also records it from the Mediterranean, in the Gulf of 
‘Marseilles. Sidebottom’s record is from the coast of the island of 
Delos. Millett records and figures it from the Malay Archipelago. 
Specimens similar to those figured by Millett have occurred at all 
of the Tortugas stations, often in considerable numbers. Millett 
notes that the largest specimens which he had were biloculine, and 
from a study of the Tortugas collection it would seem as though the 
‘species might even be better referred to Biloculina than to Triloculina. 
The adults are usually biloculine, but smaller specimens still in the 
triloculine stage are not uncommon. 
