FOEAMIXIFERA OF THE ATLANTIC OCEAN 143 



tho surface solid with large scattered foramina covered by a finely 

 perforated plate; color dark red. 



Recent. 



There seems to be but a single species, very widely distri[)uted. 



HOMOTREM.\ RUBRUM (Lamarck) 



Millepora rubra Lamarck, Hist. Nat. Aiiiin. sans Vert., vol. 2, 1816, p. 202. 



Polytrema rubra Dujardin, Hist. Nat. Zooph., 1841, p. 259. — Carpenter, 

 Parker, and Jones, Introd. Foram., 1862, p. 235, pi. 13, figs. 18-20. 



Homotrema ruhrum Hickson, Trans. Linn. Soc. London, Zool., ser. 2, vol. 

 14. 1911, pp. 445, 454, pi. 30, fig. 2; pi. 31, fig. 9; pi. 32, figs. 19, 22, 28.— 

 Pearcey, Trans. Roy. Soc. Edinburgh, vol. 49, 1914, p. 1041. — Heron- 

 Allen and Earland, Trans. Zool. Soc. London, vol. 20, 1915, p. 729. — 

 Cushman, Bull. 100, U. S. Nat. Miis., vol. 4. 1921, p. 364; Puhl. 311, 

 Carnegie Instit., Washington, 1922, p. 53, pi. 14, figs. 6-8; Special Publ. 

 No. 1, Cushman Lab. Foram. Res., 1928, pi. 52, figs. 25-27. 



Test attached, earliest chambers in a whorl, later ones forming an 

 irregular mass, honeycombed, the surface composed of a reticulate 

 pattern, the central portion of each mesh with a thin perforated plate, 

 the walls of the mesh work solid and nonporons; whole mass raised 

 into irregular subcylindrical masses in the early stages, then fusing 

 and spreading so that the whole test becomes an irregularly rounded 

 mass rising above the surface of attachment with papillae raised 

 above the rest of the surface; color bright to dull red. 



Diameter of large mass up to 8 mm. 



This species is generally distributed in the West Indian region, in 

 very warm shallow water, at the Dry Tortugas and extending to the 

 coast of Brazil. 



The Tortugas specimens showeci the tips of the test with a crown of 

 projecting spicules, evidently sponge spicules which were cemented 

 into long flexible lines forming a crown about the projecting parts of 

 the test. At the Tortugas species occurred in great numbers almost 

 covering the under sides of shell and coral fragments in shallow la- 

 goons and on dead reefs, where the temperatures at low tide were 

 often warm to the hand. 



Genus SPORADOTREMA Hickson. 1911 



Sporadoirema Hickson, Trans. Linn. Soc. Zool., vol. 14, 1911, p. 447. — 

 Cushman, Special Publ. No. 1, Cushman Lab. Foram. Res., 1928, p. 334. 

 Polytrema Carter, 1880 (not Ri.sso). 



Genoholotype — Polytrema cylindricum Carter. 



Test attached, the early stages coiled, later extending outward and 

 upward into short stout branches, numerous chambers apparent 

 about the outer end ; wall calcareous, the surface solid with scattered 

 foramina, open, not covered by a plate; color, orange or red. 



Recent. 



This genus is not known in the Atlantic. 

 2305—31 11 



