82 ANIMAL EESOURCES OF THE UNITED STATES. 



17. CORAL — Continued. 



a. Coral as a material : 



Axis of fan coral, (RMpidogorgia,) used for skimmers and 



strainers in tbe Bermudas. 

 Coral, used for building purposes. 

 Coral rock of recent formation, (Coquina,) used in Florida in 



manufacture of ornamental vases and carvings. 

 Calcined coral, used for dentifrices, as an antacid, &c. 

 Imitations of red coral in celluloid, rubber, and otber sub- 

 stances. 

 IS. INFUSORIAL EARTHS. 



a. Polishing powders, (used for polishing metals, cabinet-ware, 

 and stone :) 



Specimens of polishing-slate, tripoli, and other foreign polish- 



ing-powder. 

 Specimens of American infusorial deposits. 



b. Infusorial earths, employed in manufactures : 



Infusorial earth, used in making window and plate glass. 

 Infusorial earth, used in making soluble glass. 

 Infusorial earth, used in making mortar. 

 Infusorial earth, used in making molds for metal casting. 

 Infusorial earth, used in making filters. 

 Infusorial earth, used in making dynamite. 

 Infusorial earth, used in making fire-proof packing. 

 Infusorial earth, as an absorbent for oils and liquids. 



19. OTHER MATERIALS FROM INVERTEBRATES. 



a. From insects : 



Brazilian diamond-beetles, used in jewelry. 

 Wings of beetles, used in embroidery. 



b. From echinoderms : 



Spines of echinoids, used for slate-crayons. 



** Flexible materials. 



20. LEATHERS. (Embracing the hides in a rough state, in the various 



stages of dressing, and manufactured into shoe- 

 leather, parchment, vellum, binder's leather, 

 thongs, &c.) 

 a. Prepared from mammal skins : 



Cat-leather. 



Dog and wolf leather, used for drum-heads, &c. 



