N69

Anthocyrtidium zanguebaricum (Ehrenberg)

Anthocyrtis zanguebarica Ehrenberg, 1872a, pl. 301

Anthocyrtidium zanguebaricum (Ehrenberg), Nigrini, 1967, p. 58, pl. 6, fig. 4

DESCRIPTION "Shell rather similar in form to Anthocyrtidium ophirense. Cephalis lobate as in A. ophirense, but apical horn is much shorter, usually about equal in length to the cephalis. Thorax less campanulate, more ovate, and always smaller, both in breadth and length. Subterminal teeth, when present, are poorly developed; terminal teeth may be entirely absent, rudimentary, or in the form of inconspicuous, small triangular teeth directed either downwards or inwards." (from Nigrini, 1967).

DIMENSIONS "Length of apical horn 18-36 microns; of cephalis 27-36 microns; of thorax 63-90 microns. Maximum breadth of cephalis 18-27 microns; of thorax 63-81 microns." (from Nigrini, 1967).

REMARKS

1. For a more complete synonymy see Nigrini, 1967.

2. Benson's (1966) description and dimensions of Anthocyrtidium oxycepyhalus (Haeckel) (p. 468) are similar to the above but he includes larger forms with an angular thoracic contour and lacking subterminal teeth which may not be conspecific.

Plate 25, figure 2

N70

RECENT DISTRIBUTION 1. Nigrini, 1967, fig. 31; "Indian Ocean occurrences - A. zanguebaricum is sparsely distributed in both low and middle latitudes. Maximum abundances (up to 3% of the described population) occur in the western tropics."

2. Molina-Cruz, 1975, Code N3; used in factor analysis of southeast Pacific assemblages; cf. Appendix 10 for percent N3 at each station.