NO. 5 FORAMINIFERA FROM TRINIDAD—SAUNDERS II 
TIPHOTROCHA Saunders, new genus 
Type species—Trochammina comprimata Cushman and Bronni- 
mann, 1948, emend. Saunders. 
Diagnosis.—Test trochospiral, involute ventrally. Dorsal side flat 
or convex, ventral side concave. In well-developed specimens the 
chambers of the last whorl have inflated projections into the umbilicus. 
Wall arenaceous. The apertures of the chambers of the last whorl 
open separately into the umbilicus at the ends of the inflated chamber 
projections, if these are present. The last chamber may have a lip 
extending partially or wholly across the umbilicus and concealing all 
but the last aperture. The umbilical area may be covered by a “plate” 
formed by the coalescence of the lips of the ventral, inflated lobes of 
the chambers in the last whorl; in this case, most if not all of the 
primary apertures may be concealed. 
Remarks.—The new genus differs from Trochammina Parker and 
Jones, 1859, in that the aperture of each chamber in the last whorl 
opens separately into the umbilicus and not into the next succeeding 
chamber as in the latter. Also, the umbilicus of the new genus may 
be concealed beneath a platelike outgrowth from the chambers. A 
similar umbilical cover may be present in Siphotrochammina, which 
differs from Tiphotrocha in lacking separate apertures from the cham- 
bers into the umbilicus. 
TIPHOTROCHA COMPRIMATA (Cushman and Bronnimann) 
emend. Saunders 
PLATE 4, FIGURES I-4 
Trochammina comprimata CUSHMAN and BRoNNIMANN, Contr. Cushman Lab. 
Foram. Res., vol. 24, pt. 2, p. 41, pl. 8, figs. 1-3, 1948. 
Emended diagnosis—Shape of test: Trochospiral, compressed, 
with an irregularly lobate equatorial periphery; dorsal side slightly 
convex, ventral side concave. Axial periphery rounded ; subangular in 
very compressed forms. Wall: Thin, consisting of fine sand grains 
with little cement. Surface smooth but not polished. Color brown to 
fawn, the first whorl may be darker in color than the rest of the test. 
Chambers: Test of two to three whorls with four to six (usually 
five) chambers in the last whorl. The chambers of the early whorls 
increase regularly in size but those in the last whorl may be rather 
irregular in shape and are considerably elongated in the direction of 
coiling. The chambers of the last whorl have inflated lobes projecting 
into the umbilicus. In large specimens, the last chambers are inflated 
