NO. 5 FORAMINIFERA FROM TRINIDAD—SAUNDERS 9 
laevigata Cushman and Bronnimann. Trochammuina inflata has a 
slightly more convex dorsal surface with more deeply incised sutures 
and its last chambers are more inflated. Papers on brackish faunas 
of the coasts of North America (Phleger and Walton, 1950; Parker, 
Phleger, and Peirson, 1953; Ronai, 1955) describe as Trochammina 
inflata (Montagu) specimens that are almost certainly identical to 
Trochammina laevigata Cushman and Bronnimann. 
SIPHOTROCHAMMINA Saunders, new genus 
Type species —Siphotrochammina lobata Saunders, new species, 
Diagnosis ——Test trochospiral, involute ventrally. Dorsal side flat 
or convex, ventral side concave. Wall arenaceous; some specimens 
have very little agglutinated material on the basic “chitinous” wall. 
The last chamber has a ventral, siphonlike lobe extending partially 
across the umbilicus. The aperture is situated at the umbilical end of 
this lobe and is directed forward. The aperture of the penultimate 
chamber opens into the ventral lobe of the last chamber. A plate may 
extend across the umbilicus concealing the primary aperture; in this 
case, irregular secondary apertures are present on one or both sides of 
the plate. 
Remarks.—Siphotrochammina is closely related to Trochammina 
Parker and Jones, 1859, from which it differs in the nature of its aper- 
ture. In Trochammina the aperture is an arched slit at the inner 
margin of the ventral side of the chamber whereas in Siphotrocham- 
mina the aperture is a forward-directed, circular opening at the inner 
end of a siphonlike lobe that extends from the last chamber into the 
umbilicus. The aperture of the penultimate chamber opens into the 
“siphon” of the last chamber. Siphotrochammina is somewhat similar 
to the free stage of Tritaxis Schubert, 1920, emend. Loeblich and 
Tappan, 1955. In the emended description of this latter genus the 
aperture in the free stage is “an ovate opening at the base of the last- 
formed chamber near the umbilicus, and surrounded by a distinct 
lip . . .” (Loeblich and Tappan, 1955). 
SIPHOTROCHAMMINA LOBATA Saunders, new species 
PLATE 3, FIGURES I, 2 
Diagnosis —Shape of test: Trochospiral, with a lobate equatorial 
periphery ; dorsal side convex, ventral side slightly concave. Axial 
periphery rounded. Wall: Thin, consisting of fine sand grains with 
little cement. Surface smooth and somewhat polished. An inner “chi- 
tinous” layer is present and, in very fragile specimens, agglutinated 
