Page:Scientific results HMS Challenger vol 18 part 1.djvu/943

Rh

Definition.—Ten radial spines.

1. Litholophus decimalis, n. sp.

Ten radial spines, four-sided prismatic, with prominent smooth edges, of equal breadth throughout their whole length.

Dimensions.—Length of the spines 0.2 to 0.3, breadth 0.006.

Habitat.—Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, surface.

2. Litholophus pyramidalis, n. sp.

Ten radial spines, four-sided pyramidal, with prominent smooth edges, gradually thickened from the small pyramidal base towards the truncated distal end.

Dimensions.—Length of the spines 0.3 to 0.4, breadth in the basal part 0.002, in the middle part 0.006, in the distal part 0.012 to 0.02.

Habitat.—Central Pacific, Station 266, surface.

3. Litholophus decapristis, n. sp. (Pl. 129, fig. 2).

Ten radial spines, four-sided prismatic, with prominent, elegantly denticulated edges, of equal breadth in their whole length.

Dimensions.—Length of the spines 0.2 to 0.4, breadth 0.008.

Habitat.—Cosmopolitan; Mediterranean, Atlantic, Pacific, surface.

4. Litholophus decastylus, n. sp.

Ten radial spines, four-winged pyramidal, with broad and thin, elegantly denticulated edges, gradually thickened from the small pyramidal base towards the truncated distal end.

Dimensions.—Length of the spines 0.2 to 0.3, breadth in the basal part 0.002, in the middle part 0.005, in the distal part 0.015.

Habitat.—South Atlantic, Station 332, surface.

Definition.—Number of the radial spines variable, between ten and twenty, commonly twelve to sixteen.