Page:Scientific results HMS Challenger vol 18 part 2.djvu/675

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Definition.— with numerous hollow cylindrical or spindle-shaped tubes, which lie tangentially scattered on the surface of the spherical calymma.

Definition.— with a skeleton composed of tubular acicular pieces, which are smooth, cylindrical or spindle-shaped tangential needles, without spines and branches.

The genus Cannobelos, and the following closely allied Cannorrhaphis, represent the peculiar subfamily Cannobelida, differing from the other Cannorrhaphida in the acicular form of the pieces of the skeleton, which are tangentially scattered on the surface of the spherical calymma. The cylindrical or spindle-shaped hollow needles are smooth in Cannobelos, whilst in Cannorrhaphis they are studded with lateral spines or branches.

1. Cannobelos cavispicula, Haeckel.

Thalassoplancta cavispicula, Haeckel, 1862, Monogr. d. Radiol., p. 261, Taf. iii. figs. 10-13.

Thalassicolla cavispicula, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wis. Berlin, p. 798.

Cannorrhaphis cavispicula, Haeckel, 1881, Prodromus, p. 470.

Tangential tubes cylindrical, more or less curved, gradually tapering towards the two pointed ends. Calymma with a voluminous phæodium.

Dimensions.—Length of the tubular spicule 0.25, breadth 0.003.

Habitat.—Mediterranean, Messina, surface.

2. Cannobelos calymmata, n. sp.

Tangential tubes cylindrical, straight, of equal breadth throughout their whole length, closed by a hemispherical cap on the two rounded ends. Calymma very voluminous, with a small phæodium.

Dimensions.—Length of the tubular spicula 0.3 to 0.5, breadth 0.004 to 0.008.

Habitat.—Central Pacific, Stations 263 to 274, surface.

3. Cannobelos thalassoplancta, n. sp.

Tangential tubes spindle-shaped, straight, gradually tapering towards the two pointed ends. Calymma and the included phæodium rather voluminous.

Dimensions.—Length of the tubular spicula 0.15 to 0.2, breadth in the middle part 0.02.

Habitat.—Tropical Atlantic, Station 347, surface.