REPORT ON THE RADIOLARIA. 743 



2. Acanthometron cylindricum, n. sp. (PI. 130, fig. 2). 



Spines cylindrical, thick and long, at the central base thickened with a pear-shaped knob, and 

 with very small central fulcral pyramid, without leaf-cross. Distal apex rounded or truncated. 

 Central capsule opaque, filled with red pigment-bodies. 



Dimensions. Length of the spines 0'4 to 0'8, breadth O'Ol to 0'015. 



Habitat. Central Pacific, Stations 266 to 274, surface. 



3. Acanthometron fuscum, J. Miiller. 



Acanthometra fusca, J. Miiller, 1858, AbhandL d. k. Akad. d. "Wiss. Berlin, p. 47, Taf. xi. fig. 4. 

 Acanthometra fusca, Haeckel, 1862, Monogr. d. Eadiol., p. 377. 



Spines very thin and long, in the proximal half cylindrical, in the 'distal half conical, gradually 

 thinned towards the simple conical apex. Central base a small four-sided pyramid, without 

 leaf-cross. Central capsule opaque, filled with brown pigment-bodies. 



Dimensions. Length of the spines 02 to 0'4, breadth 0'002 to 0'004. 



Habitat. Mediterranean (Cette, Portofino, Messina). 



4. Acanthometron bulbosum, Haeckel. 



Acanthometra bulbosa, Haeckel, 1862, Monogr. d. Radio!., p. 377, Taf. xv. fig. 2, Taf. xviii fig. 2. 



Spines very thin and long, cylindrical, with simple needle-shaped apex ; in the basal part conical, 

 towards the centre much thickened, with a short four-sided fulcral pyramid, without leaf-cross. 

 Central capsule opaque, filled with brown pigment-bodies. 



Dimensions. Length of the spines' O3 to 0'5, breadth in the middle and outer part O'OOl, in 

 the basal part O'OOS to 0'012. 



Habitat. Mediterranean ; Atlantic, Station 354, surface. 



5. Acanthometron dolichoscion, Haeckel (PI. 129, figs. 6-8). 



Acanthometra dolichoscia, Haeckel, 1862, Monogr. d. Radiol., p. 377, Taf. xviii. figs. 3a, 3b. 



Spines very long and thin, cylindrical, in the thickened outer half about twice as thick as in 

 the thin inner half, at the simple apex compressed, two-edged. Central base little thickened, with 

 a small four-sided pyramid, without leaf-cross. Central capsule transparent, whitish or yellowish. ' 



Dimensions. Length of the spines 0'6 to 0'8, breadth in the proximal part 0'004, in the distal 

 part 0-008. 



Habitat. Mediterranean (Messina, Portofino), surface. 



6. Acanthometron conicum, n. sp. 



Spines short and thick, conical, gradually thinner from the thick conical base towards the 

 simple apex. Central part of the base with a large fulcral pyramid, but without leaf-cross. 

 Central capsule transparent, colourless (?). 



Dimensions. Length of the spines 0'08 to 012, basal breadth 0'02. 



Habitat. North Pacific, Station 244, surface. 



