10 SHALLOW-WATER FORAMIMFERA OF TORITTGAS REGION. 



COLOR IN LIVING SPECIMENS. 



Most of the Miliolidir, unless incrusted with colored sand-grains, 

 have little color in dried tests. In the living state, however, there 

 is often much color, due to different causes. In the Quinqueloculine 

 group there is often a beautiful light-pink color in live specimens, 

 due to the color of the protoplasm, as may be seen in that projecting 

 from the aperture. This is often sufficient to color the whole test, 

 especially with transmitted light. 



In Orhitolites duplex there is usually a salmon-color in living 

 specimens which do not have commensal alga?. The outer one or 

 two annuli usually are filled with nearly colorless protoplasm. 

 Often the general color is due to algae, as will be noted later. 



In the Rotaliidse there is often a reddish-brown color, in the 

 earlier chambers at least. Instead of being caused by the protoplasm 

 alone, it seems in some species at least (see Tretomphalus bulloides, 

 p. 42) to be due to a thin fining of colored material which is distinct 

 from the calcareous wall of the test. In Truncatulina rosea there is 

 developed a peculiar rose-red color which persists and colors nearly 

 the whole test. A bright red color is also characteristic of 

 Homotrema, which is abundant in the reefs. In the Globigerinidae, 

 especially in Globigerina rubra, there is again a distinctly rose color, 

 especially in the early chambers. 



Found with the Homotrema is a small crab with reddish spots of 

 the same color as the Homotrema, the remainder of the carapace and 

 legs of the color of the dead coral. The resemblance is very striking. 



COMMENSAL ALG^. 



The association of unicellular algae with certain of the Foraminifera 

 has been known for some time. There is evidently a commensal 

 relation between the two, although the exact interrelations have not 

 been definitely made out. In Iridia diaphana there are often great 

 numbers of a small unicellular alga, somewhat fusiform in shape, of 

 a brownish color, and about 0.006 to 0.007 mm. in length. These 

 are usually associated with the pseudopodia in Iridia. When the 

 pseudopodia are extended and active, nearly all the algae are outside 

 the actual test, and when quiescent they are apparently stored in 

 the area at the peripheral portion of the central mass and in the 

 radial canals. 



In Orbitolites duplex there are bodies in the test, usually in the 

 more central portions. These are brownish and completely pack 

 the chambers, irregularly rounded and about 0.006 mm. in diameter. 

 These are very different from the algae noted in Iridia. 



In the Philippine collections, green algae were noted in great 

 abundance in Orbitolites and Cyclolypeus, but no green ones were 

 noted at the Tortugas. 



