Page:Scientific results HMS Challenger vol 18 part 2.djvu/825

Rh The genus Haeckeliana comprises the spherical Circoporida, with dimpled, porcellanous shell, which are widely distributed, but rather rare, in depths between 2000 and 3000 fathoms. All the known species (six in number) are very closely related, and though the extreme forms appear very different in size and structure, they are so connected by a continuous series of intermediate forms, that they may be regarded as varieties of a single species, first observed by Dr. John Murray, and called by him Haeckeliana porcellana. The number of radial spines may be from sixteen to fifty-five, and is usually between thirty and forty. Each is surrounded by a basal coronet of aspinal pores, usually five, more rarely four or six; the number, however, is not constant in any one species. Each coronet is armed with an outer ring of by-spines. The surface of the shell between the coronets is dimpled. The mouth (Pl. 114, fig. 3) is about as large as a corona, and also armed with a ring of by-spines. The structure of the thick porcellanous shell and the radial spines is different from the other Circoporida.

1. Haeckeliana porcellana, John Murray (Pl. 114, fig. 6).

Haeckeliana porcellana, John Murray, 1879, in schedulis, Chall. Coll.

Shell with forty to forty-five coronets, the majority of which have five pores (more rarely four or six). Coronets broader than their intervals, and twice as broad as the length of the by-spines. Dimples subcircular, of the same breadth as the pores. Main-spines about as long as the radius.

Dimensions.—Diameter of the shell 0.37 to 0.42, of the coronets 0.06 to 0.07.

Habitat.—South Pacific, Stations 289 to 293, depth 2025 to 2550 fathoms.

2. Haeckeliana maxima, n. sp. (Pl. 114, fig. 5).

Shell with fifty to fifty-five coronets, the majority of which have six pores (more rarely five or seven). Coronets broader than their intervals, and eight to ten times as broad as the length of the by-spines. Dimples irregularly polygonal, of about the same breadth as the pores. Radial main-spines about as long as the diameter of the shell.

Dimensions.—Diameter of the shell 0.5 to 0.52, of the coronets 0.08 to 0.09.

Habitat.—Equatorial Atlantic, Station 347, depth 2250 fathoms.

3. Haeckeliana lamarckiana, n. sp. (Pl. 114, fig. 4).

Shell with thirty-five to forty coronets, the majority of which have five pores (more rarely six or four). Coronets broader than their intervals; each funnel-shaped pore on the inside with a circle of small conical thorns. By-spines rudimentary or wanting. Dimples irregularly polygonal, half as broad as the pores. Radial main-spines shorter than the radius.

Dimensions.—Diameter of the shell 0.38 to 0.45, of the coronets 0.06 to 0.07.

Habitat.—South Atlantic, Stations 318 to 333, depth 2000 to 2900 fathoms.