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



the capsule one single very large spiculiim, whilst the others are much smaller (fig. 3). All the 

 alveolated capsules are placed in one single stratum on the surface of the jelly-like spherical 

 ccenobium, comparable to the blastoderm-cells of a blastula. 



Dimensions. — Diameter of the central capsules 0'08 to Ol, of the alveoles 0'2 to 0'4, length of 

 the spicula 0"1 to 0'3. 



Eahitat. — South Pacific (Juan Fernandez), Station 300, surface. 



12. SphcBrozoum verticillatum, n. sp. (PI. 4, fig. 7). 



Spicula all geminate-triradiate, with a short simple middle rod and three much longer arborescent 

 shanks on each end of it. Shanks sti-aight, slender, pme-shaped, each in the distal Iialf with three 

 to four elegant verticils of thorny lateral branches. 



Dimensions. — Diameter of the capsules O'l to 0'12, middle rod of the spicula 0'03 to 0'05, 

 shanks O'l to 0'15. 



Hahit'at. — Indian Ocean, Ceylon, Haeckel ; Madagascar, Eabbe ; surface. 



13. Spharozoum octoceras, n. sp. 



Spicula all geminate-quadriradiate, with a short simple middle rod and four diverging shanks on 

 each end of it. Shanks smooth, irregularly curved or bent, three to six times as long as the middle 

 rod. It may be regarded as the social form of Thalassoxanthiwm octoceras (PI. 2, fig. 6). 



Dimensiojis. — Diameter of the capsules 0-12 to 0'16, middle rod of the spicula 0"02, shanks 

 0-01. 



Heditat. — Australia, south coast, Faber; Station 1G3, surface. 



14. Sphcerozoum quadrigeminum, n. sp. 



Spicula all geminate-quadriradiate, with a long tliick middle rod and four shorter diverging 

 shanks on each end of it. Shanks straight, thorny. 



Dimensions. — Diameter of the capsules 0-06 to 0-08, length of the spicula O'Oo to 015. 

 Habitat. — North Atlantic, Azores, Station 354, surface. 



15. SphcBrozoum araucaria, n. sp. 



Spicula all geminate-quadriradiate, with stout straight middle rod and four longer diverging 

 shanks on each end of it. Shanks arborescent, with six to twelve thorny lateral branches. 

 Dimensions. — Diameter of the capsules 01 to 0'15, length of the spicula 0"05 to 01. 

 Habitat. — South Atlantic, coast of Brazil, Eabbe ; surface. 



16. SphcBrozoum arborescens, n. sp. (PI. 4, fig. 8). 



Spicula all geminate-quadriradiate, with a stout straight middle rod and four longer diverging 

 shanks on each end of it. Shanks arborescent, pine-shaped, with four to six \erticLls of lateral 

 branches, which again are ramified and thorny. 



