Staurocucumis

Ekman, 1927

5 species

Fairly small, fusiform cucumariids with no distinct difference between bivium and trivium. With ten equal tentacles and with water vascular appendages in two alternating rows along the ambulacra, and totally lacking in the interambulacra. Calcareous ring well developed and simple, i.e. without any posterior prolongations. Intestine with muscular stomach. Polian vesicle and stone canal single, and respiratory trees more or less reduced. Retractor muscles, for the most part free, only united with the longitudinal muscles by a web close to their base. Calcareous deposits in the body wall proper exclusively four armed crosses with perforated ends and an eccentrically placed spire or with no spire, and then with one arm spinous, resembling a spire. This latter case more common in larger specimens. 2 sub genera. (Heding, 1942)

ten equal tentacles. The calcareous ring simple, without forked tail; in older animals more or less regressive. The retractors are connected throughout their length to the longitudinal muscles by means of a membrane. In the surface of the skin there are cup-like structures. Under these there are plates with handles and plates which are transformed into table-like deposits. This genus can undergo change and diminishing of calcareous deposits. (Panning, 1949)

The genus was erected to accommodate 5 species of the order Dendrochirota with a unique type of ossicle. In these species, formerly in the genus Cucumaria, the juvenile ossicles are primary crosses with only arms and one single columned vertical apophysis. The genus originally comprised two antarctic shallow-water species and three deep-species, of which two, Staurocucumis abyssorum (Théel, 1886) and Staurocucumis sluiteri (Ohshima, 1915) have since been synonymized. (Hansen, 1988)