96 THE VOYAGE OF H.M.S. CHALLENGEE. 



Dimensions. — Diameter of the shell 01 to 0-12, of the pores 0'002 to O'OOS, breadth of the 

 bars 0-004 to O'OOS. 



Habitat. — Tropical and subtropical zone of both hemispheres, widely distributed ; Canaries. 

 Azores, Cape Verde Islands, Guinea Coast, Brazil Coast, Indian Ocean, Madagascar, Ceylon, surface. 



Subgenus 2. Dyscollosphcera, Haeckel. 



Definition. — Shell uot a regular sphere, but ii-regular roundish, in all degrees of 

 variation between subspherical and polyhedral or quite irregular forms. 



4. CoHosphcBra huxleyi, J. Miiller. 



CoUosphcera huxlciji, J. Midler, 1855, Abliandl. d. k. Akad. d. Wiss. Berlin, pp. 55-59, Taf. viii. 



figs. 6-9. 

 Collosphara huxleyi, Haeckel, 1862, IMonogr. d. Eadiol., p. 534, Taf. xxxiv. 

 Collosjj/uera huxleyi, Cieukciwski, 1871, Arcbiv f. mikrosk. Auat., Bd. vii. p. 374, Taf. xxix. 



figs. 1-6. 

 Collo)ph(era ligurina, J. ^Miiller, 1856, Monatsber. d. k. Akad. d. Wiss. Berlin, p. 481. 

 Thalassicolla punctata, var., Huxley, 1851, Ann. and Mag. Nat. Hist., ser. 2, vol. viii. ]). 434, 



pi. xvi. fig. 6. 



Shell subspherical, somewhat irregular, sometimes with more or less superficial impressions, 

 with irregular network of roundish meshes. Eight to sixteen meshes in the half meridian of the 

 shell, one to three times as broad as their bars. Very variable, with direct transition-forms to other 

 species of this genus, especially to Collospha;ra globularis, Collosphcora tubcrosa, Collosplia:ra 2i>ji'iformis, 

 and Collosphocra polyedra. 



Dimensions. — Diameter of the sheU O'l to O'lG, of the pores 0'004 to 0'012, of the bridges 

 0-003 to 0-006. 



Habitat. — Cosmopolitan ; common in the greater part of the warmer seas, surface. 



5. CollosphcBra pohjgona, n. sp. (PL 5, fig. 13). 



Collosphmra huxleyi var., Haeckel, 1862, Monogr. d. Kadiol., Taf. xxxiv. fig. 5. 



SheU irregular polygonal, with very delicate, irregular network of polygonal meshes, four to 

 twelve times as broad as the bars. Ten to twenty pores on the half meridian of the shell. 



Dimensions. — Diameter of the shell 0-1 to 0-2, of the pores 0-012 to 0-004, of the bars Q-OOl 

 to 0-002. 



Habitat. — Mediterranean, Atlantic, surface; Stations 348 to 354. 



6. CollosphcBra piyriformis, Haeckel, n. s]!. 



SheU irregular, rounded, ovate or pear-shaped, with irregular network of rounded or nearly 

 ])i>lygonal meshes. Ten to twenty meshes in the half meridian of the shell, one to three times as 

 broad as the bars. Commonly one large opening (two to three times as broad as the largest 



