POEAMINIFERA OF THE KERIMBA AECHIPELAGO. 729 



HOMOTREMA HicksOTl. 



439. Homotrema rubrum (Lamarck). 



Millepora rubra Lamarck, 1816, etc., ASV. vol. ii. p. 203. 

 Polytrema rubra Dujardin, 18il, HNZ. p. 259. 



„ „ Carpenter, Parker, & Jones, 1862, IF. p. 235, pi. xiii. figs. 18-20. 



Homotrema rubrum liickson, 1911, P. pp. 445, 454, pi. xxx. fig. 2, pi. xxxi. fig. 9, pi. xxxii. 

 figs. 19, 22, 28. 



5 Stations. 



Eecognizable specimens were obtained, the best at Stn. 11. At Stn. "? X fragments 

 of the terminal portion were observed with an investing crown of spicules. The 

 species is probably universally distributed over the area, but, owing to the lack of 

 suitable coarse material, the records are few. At Stn. 11a single large colourless 

 specimen was seen. Hickson in his paper {supra) remarks on the fact that the red 

 colour in Polytrema and Homotrema is remarkably constant, but that he had met 

 with many white specimens from various localities which he thought were in all cases 

 dead, the whiteness being due to post-mortem discoloration. In the Kerimba specimens 

 the shell is in a remarkably good state of superficial preservation, and it is difficult 

 to understand that the colour can have disappeared after death in view of the fact that 

 other specimens evidently long dead, and partially decomposed, have preserved their 

 vivid red tint. 



At Stn. 11 a iew young individuals were found in a free condition, varying in 

 colour from deep ruby-red to very pale pink. We have submitted these to Prof. 

 Hickson, ^^ho has no hesitation in accepting the reference of the deep-coloured 

 individuals to Homotrema, and is inclined to the opinion that the pale ones are 

 similarly attributable. His diagnosis is confirmed by the measurements of the 

 foramina. 



Sporadotrema Hickson. 



440. Sporadotrema cylindricum (Carter). 



Polytrema cylindricum Carter, 1880, etc., SGM. 1880, p. 441, pi. xviii. fig. 1. 



Brady, 1884, FC. p. 7:20. 

 Sporadotrema ci/lindricum Hickson, 1911, P. p. 417, pi. xxx. figs. 3-7, pi. xxxi. figs. 10-17, 

 pi. x.\xii. figs. 20, 21, 24., 29, 32, 33. 



2 Stations. 



A few large but undoubted fragments, orange-red in colour, at Stns. 9 and 11. 

 The paucity of suitable material probably accounts for the isolated occurrence of 

 these forms. 



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