PLATE II 



Fig. I. Envelope-shaped crystals of hydrated calcium oxalate, €30^04 . 

 2H2O, from the Weddell Sea (' Scotia', St. 286, 4550 m.). x 15. 



Fig. 2. Lenticular crystals of gypsum, CaS04.2H20, from the Weddell 

 Sea ('Scotia', St. 391, 4809 m.). x 10. 



Figs. 3 and 4. X-ray photographs of a crystal of hydrated calcium 

 oxalate from the Weddell Sea. Both photographs were taken with un- 

 filtered copper radiation and with the same cylindrical camera diameter 

 6-04 cm. A length of 8-5 cm. on the original films is equal to 10 cm. on 

 the reproduced figures. Fig. 3 shows the photograph obtained when the 

 crystal is rotated about the [100] axis. Fig. 4 is the corresponding photo- 

 graph for the [001] axis. 



