Siphomarginulina McCulloch 1981

Siphomarginulina es un género de foraminífero bentónico de la subfamilia Lenticulininae, de la familia Vaginulinidae, de la superfamilia Nodosarioidea, del suborden Lagenina​ y del orden Lagenida.​ Su especie tipo es Siphomarginulina hybrida. Su rango cronoestratigráfico abarca el Holoceno.

Test elongate, compressed, periphery rounded and noncarinate, early chambers planispirally enrolled, only three to four chambers in the coil, final few chambers uncoiled and rectilinear, sutures radial in the early coil, oblique in the uncoiling part; wall calcareous, hyaline, translucent, finely perforate, surface smooth; aperture rounded at the dorsal angle, produced on a neck and bordered by a distinct lip with crenulate margin. Holocene; Caribbean Sea. (Loeblich & Tappan, 1987, Foraminiferal Genera and Their Classification)