2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134 
Ammoastuta inepta (Cushman and McCulloch) and species of Ammo- 
baculites. The arenaceous tests are all thin walled and fragile, often 
with a “chitinous” inner layer which may be the only wall in the 
early chambers. Several of the lituolid genera develop multiple aper- 
tures, at least in the late stages (Ammoastuta, Haplophragmium, and 
Trochamminita). It is possible that this is an adaptation to the en- 
vironment. This being the case, the danger of erecting new genera 
based on multiple apertures alone becomes apparent, as has been 
stressed previously (e.g., Glaessner, 1955). 
Two new genera, Siphotrochammina and Tiphotrocha, are erected 
for Trochamminidae with stable apertural features that prevent their 
inclusion in the genus Trochammina. It is to be expected that this 
specialized environment should cause the development of new genera 
especially adapted to it. Their recognition is of value, as they may be 
of great help in the detection of similar biofacies in fossil deposits. 
All figured types are deposited in the United States National Mu- 
seum, Washington, D. C. An additional set of types will be deposited 
in the British Museum (Natural History), London. 
Sincere thanks are due Dr. Helen Tappan Loeblich and Dr. Alfred 
R. Loeblich, Jr., who have been consulted at all stages and who have 
compared the author’s material with that in the U. S. National Mu- 
seum. The excellent illustrations were prepared by Patricia Isham, 
scientific illustrator at the U. S. National Museum. Dr. H. M. Bolli 
has read the manuscript and made many valuable suggestions for 
which the author is indebted to him. Acknowledgment is made to the 
Management of Trinidad Leaseholds, Ltd., for the use of laboratory 
facilities. 
SYSTEMATIC DESCRIPTIONS 
Family LITUOLIDAE Reuss, 1861 
Genus HAPLOPHRAGMOIDES Cushman, 1910 
HAPLOPHRAGMOIDES MANILAENSIS Andersen 
PLATE I, FIGURES I, 2 
Haplophragmoides manilaensis ANDERSEN, Contr. Cushman Found. Foram. Res., 
vol. 4, pt. I, p. 22, pl. 4, fig. 8, 1953. 
Diagnosis—Shape of test: Planispiral, completely or almost com- 
pletely involute, with a lobate equatorial periphery ; area around the 
umbilicus depressed relative to the periphery. Axial periphery rounded. 
Wall: Fine sand grains with little cement; an inner, flexible, “chitin- 
ous” layer is exposed on abraded specimens where the agglutinated, 
outer layer has been removed. The surface exhibits a fine “sugary” 
