48 THE VOYAGE OF H.M.S. CHALLENGER. 



than the geiiiinate-forked, but sometimes the contrary is the case. On their variability compare 

 the general remarks on the genns, and the chapter on " Transformation " in the general introduction. 



Dimensions. — Length of the simple spicula 0'05 to O'l, of the middle rod of the forked 

 spieula 0-05 to 0-08, of their shanks 0-01 to 0-03. 



Habitat. — Mediterranean, Naples, Spezzia, surface. 



7. Rhajohidozoum patayonicum, n. sp. 



Spicula mixed, of two different kinds, simple needles and geminate-triradiate. Simple rods, 

 like those of Bdonozoum spinulosum, straight, thorny, pointed at both ends. Geminate spicula 

 double-triradiate, like those of S-phwrozoum punc.tatum, composed of a simple, short, axial rod and 

 three simple pointed shanks on each end of it. Shanks straight, thorny, with many small spinules, 

 commonly somewhat longer than the middle rod. (Often some of the spicula of both kinds are 

 smooth, not thorny, or not straight, but a little curved, or a few forked or four-radiated geminate 

 spicula are mingled with the others.) 



Diinensions. — Diameter of the central capsules 0-08 to 0-2, length of the simple spicula Ol to 

 0-15, of the geminate 0-08 to 0-16. 



Habitat. — South Pacific, west coast of Patagonia, Station 302, surface. 



8. Rhaphidozoum ascension is, n. sp. 



Spicula mixed, of two different kinds, simple needles and geminate-triradiate ; both kinds 

 thin, smooth, without spinules. Simple needles somewhat curved, C- or S-shaped. Geminate 

 spicula double-triradiate, composed of a simple, short, straight axial rod and three slender curved 

 shanks on each end of it. Shanks two to four tunes longer than the middle rod. (Sometimes few 

 simple hexaradiate and geminate tetraradiate spicula are mingled.) 



Dimensions. — Diameter of the central capsules 012 to 0'15, length of the simple spicula O'l, 

 of the double-ti'iradiate 0'05 to 0'2. 



Habitat. — South Atlantic, off Ascension Island, Station 342, surface. 



9. Rhcvphidozowni capense, n. sp. 



Spicula of two different kinds ; one kind simple, needle-shaped, straight, pointed at both ends, 

 the other kind geminate-quadriradiate, with a stout short middle rod and four longer bent 

 shanks on each end of it. Botli kinds smooth. 



Dimensions. — Diameter of the capsules 0-2 to 0-25, length of the simple needles 001 to O'S, 

 of the geminate spicula 0"05 to 0'15. 



Habitat. — Cape of Good Hope (Agulhas), Station 142, surface. 



10. Rhaphidozoum australe, n. sp. 



Spicula of two different kinds ; one kind simple, needle-shaped, curved-; thin ; the other kind 

 geminate, with a variable nmnber of shanks on both ends of the shorter middle rod, often 



