OF SEVERAL PARTS OF WESTERN ASIA. 421 



But they show, also, that these rocks are probably a rich repositoiy 

 of zeolitic and chalcedonic minerals; and, therefore, I append a cat- 

 alogue, although it has long been known that that part of India 

 afforded such specimens, and it may be that tliis particular locality 

 has been described. 



Nos. 55G to 559. Compact basalt, or greenstone : the common 

 rock. 



Nos. 5G0 to 565. Tufa, or toadstone : the cavities filled by green 

 earth, heulandite, and calcareous spar. 



Nos. 566, 567. Amygdaloid : cavities filled with beautiful green 

 earth (?) and natrolite, or mesotype, in silken tufts. 



Nos. 568 to 573. Amygdaloid : the cylindrical cavities filled with 

 chalcedony, coated by green earth, calcareous spar, quartz, and zeo- 

 litic minerals. 



Nos. 574 to 579. Trap tufa, with nodules of calcareous spar and 

 zeolites ; except No. 577, which is brick-red amygdaloid, with druses 

 of calcareous spar. 



No. 581. Stalactical chalcedony, with zeolites. 



No. 582. Chalcedony, having the form and appearance of a veg- 

 etable stem, an inch and a half in diameter. 



Nos. 583 to 587. Geodes of crystallized quartz. Crystals hexahe- 

 drons, with hexahedral summits. 



No. 589. Quartz geode : crystals six-sided prisms, with trihedral 

 summits. 



Nos. 590 to 592. Stalactical quartz : the cylinders from an inch 

 and a half to three inches in diameter, and often sLx inches long : 

 sometimes compact, with a mamillary or semi-crystalline surface : 

 sometimes the crystals have trihedral summits. 



Nos. 594 to 600. PJiomboidal crystals of calcareous or Iceland 

 spar : generally transparent, sometimes smoky. 



No. 605. Soft compact limestone : a common rock. 



No. 606. Thomsonite : in radiated masses, four inches long. 



No. 607. Stilbite, in radiating masses. 



Nos. 608, 609. Ciystallized Apophylhte, with quartz. The crys- 

 tals show two four-sided pyi-amids, shghtly truncated at the summit, 

 and at their bases : but the faces of the original primary right square 

 prism, are almost obliterated. 



No. 613. Brain Coral (Meandrina), from the island of Zanzibar, 

 broken from a rock three hundred feet above the ocean. 



