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GINSBURG, LLOYD, STOCKMAN AND MCCALLUM 



[CHAP. 22 



Fig. 3. Chambers and crusts. 



A. Assorted molluscan chambers showing some of the variations in size, shape and 

 shell thickness. 



B. Assorted chambers of Forammifera and ostracods showing some of the variations in 

 size, shape and wall thickness. 



C. The echinoid Clypeaster roseaceus. Left, a living specimen; right, an empty test 

 collected from the bottom. 



D. Submarine meadow of turtle grass, Thalassia testtidinum, off the Florida Keys. 

 Notice the white incrustations on the leaves (see Fig. 3E for detail). 



E. Crusts of blades of turtle grass. The lobate areas are a red alga Melohesiait). The 

 branching network is perhaps an irregular foraminifer. The other irregularly shaped 

 granular areas may be agglutinating Foraminifera. 



F. Crust. Left, an incrustation of coralline algae on a gastrapod shell; right, the hydro- 

 coral, Millepora, incrusting an alcyonarian. 



