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



Subgenus 3. Haliommilla, Haeckel. 



Definition. Pores of the cortical shell irregular, of different size and form ; spines 

 covering the entire surface (commonly one spine at each nodal-point). 



20. Haliomma capillaceum, Haeckel. 



Haliomma capillaceum, Haeckel, 1862, Monogr. d. Radiol., p. 426, Taf. xxiii. fig. 2. 



Cortical shell very thin walled, seven to eight times as broad as the medullary shell, both with 

 irregular, polygonal pores, and very thin thread-like bars ; outer pores twice to three times as broad as 

 the inner. Eadial spines very numerous, straight, bristle-shaped, about as long as the diameter of 

 the medullary shell. 



Dimensions. Diameter of the outer shell 0'2, inner 0'025 to 0'03 ; outer pores 0'02 to 0'04, 

 inner 0-008 to 0-016, bars O'OOl ; length of the spines 0'02 to 0'03. 



Habitat. Mediterranean (Messina), Atlantic (Canary Islands), surface. 



21. Haliomma erinaceum, Haeckel. 



Haliomma c.rinaceum, Haeckel, 1862, Monogr. d. Radiol., p. 427, Taf. xxiii. (igs. 3, 4. 



Cortical shell thin walled, seven to eight times as broad as the medullary shell, both with 

 irregular, polygonal pores, two to ten times as broad as the bars, outer pores much larger than the 

 inner. Eadial spines very numerous, bristle-shaped, as long as the diameter of the medullary 

 shell, the majority or all being either curved or obliquely depressed, the greater part neither straight 

 nor radial. 



Dimensions. Diameter of the outer shell 0'2, inner 0'025 to 0'03 ; outer pores O'OOS to 0'03, 

 inner O'OOS to O'OIG, bars 0'002 to 0'004; length of the spines 0'03. 



Habitat. Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface. 



22. Haliomma tenellum, Haeckel. 



Haliomma tenellum, Haeckel, 1862, Monogr. d. Radiol., p. 428. 



Haliomma spinuloso affine, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 40, Taf. iv. 

 fig. 7. 



Cortical shell thin walled, three times as broad as the medullary shell, with irregular, roundish 

 pores, and very thin bars. Pores of the inner shell regular, circular. Eadial spines very numerous, 

 bristle-shaped, straight, as long as the radius of the outer shell. 



Dimensions. Diameter of the outer shell 015, inner O'Oo ; outer pores O'OOS to O'OIG, inr.er 

 005 ; length of the spines 0'07. 



Habitat. Mediterranean (Nice) ; Atlantic, Stations 349 to 354, surface. 



