N71

Androcyclas gamphonycha (Jorgensen)

Pterocorys gamphonyxos Jorgensen, 1899, p. 86

P. theoconus Jorgensen, P. ambycephalis Jorgensen, 1899, p. 86

Androcyclas gamphonycha Jorgensen , 1905, p. 139, pl. XVIII, figs. 92-97; Hays, 1965, p. 178, pl. III, fig. 2

DESCRIPTION

"Test campanulate, consisting of three segments and a heavy three-bladed apical spine. Cephalis generally merges with thorax without any definite stricture, but some specimens, probably juvenile, have a weak collar stricture. Cephalis hemispherical to cylindrical; pores circular, arranged in longitudinal rows, four to five pores per row, equal in diameter to width of bars. Thorax campanulate; pores generally arranged in longitudinal rows, some with polygonal borders. Lumbar stricture distinct accompanied by an internal septal ring. Abdomen cylindrical to conical, inflated, of variable length; pores large and irregular in size, shape, and arrangement, distinctly larger than those of thorax, 5-10 times width of bars. By-spines short and slightly curved, reaching their maximum development on the broadest part of the abdomen. Mouth constricted about three-quarters the diameter of broadest part of abdomen.

"The internal skeleton has been described by Jorgensen [1905, p. 139], and the specimens examined from the Antarctic agree with his description." (from Hays, 1965).

A. gamphonycha may be distinguished from Lamprocyrtis heteroporus (Hays) (Lamprocyclas heteroporus in Hays, 1965) by its conical rather than cylindrical abdomen and by its generally larger size.

DIMENSIONS "Length of apical horn 30-60; of cephalic 18-30; of thorax 25-45; of abdomen 25-100; maximum breadth 90-130." (from Hays, 1965).

REMARKS

1. This species is very similar to species of Lamprocyclas, but it is retained in the genus Androcyclas until the evolution of each genus can be determined.

Plate 25, figure 3

N72

RECENT DISTRIBUTION

1 . Hays , 1965 , fig. 16 ; "Androcyclas gamphonycha has been observed only in sediment samples taken north of the Polar Front within the area studied. It has not been reported from the equatorial regions but was observed in North Atlantic cores SP 11-2, 62 ° 17'N, 15 ° 30'W, and A-157-5, 48 ° 55'N, 36 ° 51'W. Jorgensen originally described Androcyclas gamphonycha from off the coast of Norway and suggested that it was a temperate oceanic form.

"Androcyclas gamphonycha was not found in zone phi."

2. Lozano, 1974, Fig. IV-9; "This species is found to be more abundant between 40 ° and 45 ° S where percentages over 0.5 are more common. This is the latitude where generally the abundance of subtropical species decrease sharply to the south and Antarctic species practically disappear to the north. A. gamphonycha reaches a maximum of 1.2 percent in core RC15-96. This species is the only one of those considered in this study with a marked preference for subantarctic waters. It is found in sediments under February sea surface temperatures between 5 ° and 21 ° but it seems to prefer waters between 10 ° and 15 ° C. It is found in percentages greater than 0.5 only under waters between 8 ° and 17 ° C."