Page:Scientific results HMS Challenger vol 18 part 1.djvu/325

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Definition.— with simple shells, the pores of which are prolonged into external simple radial tubuli with fenestrated walls; outer mouth of the tubuli armed with a coronal of spines.

The genus Coronosphæra differs from Solenosphæra by the coronated mouth of the tubuli, from Trypanosphæra by the fenestration of the walls of the tubuli.

1. Coronosphæra diadema, n. sp. (Pl. 7, fig. 3).

Shell spherical or subspherical, with a variable number (fifteen to twenty) of short, coronal-like tubules, irregularly scattered, about half as long as the radius of the shell. Outer aperture of the tubuli irregularly dentated, a little dilated, and not much broader than the inner aperture, one-half or one-third as broad as the shell radius. Pores of the shell and of the tubuli circular or roundish, very irregularly scattered, mostly one-half or one-third as broad as the bars.

Dimensions.—Diameter of the shell 0.11 to 14, of the pores 0.002 to 0.004, of the bars 0.006 to 0.012; length of the tubuli 0.03, inner aperture 0.02 to 0.03, outer aperture 0.03 to 0.04.

Habitat.—Central Pacific, Stations 268 to 270, depths 2550 to 2925 fathoms.

2. Coronosphæra calycina, n. sp. (Pl. 7, fig. 4).

Shell spherical or subspherical, with a variable number (eight to twelve) of large, funnel-like tubules, irregularly scattered, about as long as the radius of the shell. Outer aperture of the tubuli irregularly dentated, much dilated, somewhat broader than the shell radius, three to four times as broad as the inner circular aperture. Pores of the shell and of the tubuli circular or roundish, of very different size, one to three times as broad as the bars.

Dimensions.—Diameter of the shell 0.1 to 0.3, of the pores 0.003 to 0.01, of the bars 0.002 to 0.004; length of the tubuli 0.1, inner aperture 0.02 to 0.03, outer aperture 0.06 to 0.18.

Habitat.—Central Pacific, Stations 271, 272, depths 2425 and 2600 fathoms respectively.

3. Coronosphæra convolvulus, n. sp.

Shell irregular roundish, with a variable number (five to ten) of long, curved tubules, about as long as the shell diameter. The inner half of the tubuli is narrow, cylindrical; the outer half funnel-like dilated, similar to the flower of Convolvulus. The outer aperture is elegantly dentated, five to six times as broad as the inner aperture. Pores of the shell and of the tubuli very irregular roundish, about as broad as the bars.

Dimensions.—Diameter of the shell 0.08 to 0.09, of the pores and bars 0.004 to 0.008; length of the tubuli 0.07 to 0.1, inner aperture 0.01, outer aperture 0.05.

Habitat.—Tropical Atlantic, Station 347, surface.