REPORT ON THE RADIOLARIA. 101 



roundish pores of very different form and size, one to four times as broad as their bars. Spines 

 conical, irregularly diverging and curved, their hollow base perforated by several pores, not longer 

 than the diameter of the largest pores. 



Dimensions. Diameter of the shell 01 to 0'2, of the pores O'OOl to 0'04 ; length of the spines 

 0-01 to 0-02. 



Habitat. Mediterranean, Messina ; Canary Islands, Haeckel. 



5. Acrosphcera collina, n. sp. (PI. 8, fig. 2). 



Shell quite irregular, polyhedrical, hilly, with a variable number (eight to sixteen) of large conical 

 hill-like prominences ; every cone or hill about as high as broad, perforated by the same pores as 

 the shell, on its top bearing a larger irregular roundish pore, and on its edge one single bristle-like 

 spine, not larger than the diameter of this pore, obliquely inserted. In the half meridian of the 

 shell twenty to thirty irregular roundish pores of very different size, one to six times as broad as the 

 bars. A very characteristic species, closely resembling the following Odontosphcera. 



Dimensions. Diameter of the shell 0'15 to 0'25, of the pores 0'005 to 0'02 ; length of the 

 spines O'Ol to 0'02, height of the hills from which they rise 0'03 to 0'04. 



Habitat. North coast of New Guinea, Station 218, surface. 



6. Acrosphcera itiflata, n. sp. (PI. 5, fig. 7). 



Mazosphcem inflata, Haeckel, 1879, Atlas, loc. eit. 



Shell more or less irregular, polyhedral, hilly, with a variable number (six ,to twelve) of large 

 pyramidal, hill-like prominences ; every hill about as high as broad, on the top a strong conical, 

 radial, or obliquely inserted spine, inflated, with three to six very large polygonal meshes, much 

 larger than the other pores between the hills, which are also polygonal, two to six times as broad 

 as the bars. Ten to fifteen pores on the half meridian. 



Dimensions. Diameter of the shell O'l to 0'14, of the largest pores 005, of the smallest 

 0-005 ; length of the spines 0'02 to 0'03. 



Habitat. North Atlantic, Station 64, surface. 



Genus 34. Odontosphcera? n. gen. 



Definition. C ollosphaerida with simple shells, the outside of which bears 

 single scattered spines, one single spine on the margin of each larger pore. 



The genus Odontosphcera is distinguished from the foregoing Acrosphcera by the 

 peculiar disposition of the spines, which are not scattered on the outside of the shell 

 between the pores, but so disposed that each larger pore is protected by one single 

 spine, obliquely placed over it. 



1 Odontospltfera = Teeth-sphere ; <i8o:/f, aQatoa. 



