242 Field Museum of Natural History — Reports, Vol. III. 



bearing regions of Lake Superior, large specimens of basalts, lavas, 

 slates, etc., and several series of structural specimens illustrating den- 

 drites, jointing, faulting, folding, cementation, etc. In Hall 67 in 

 addition to the specimens of marbles and building stones previously 

 reported as installed, about one hundred specimens which had been 

 obtained from various sources and not hitherto exhibited on account 

 of being of unsuitable size have been reduced to standard sizes, pol- 

 ished, and placed on exhibition. Six Alabama marbles in polished 

 slabs 9x16 inches received by gift form another valuable addition to 

 the collection. At present the collections exhibited in this hall include 

 over seven hundred specimens installed in eight wall cases, four center 

 cases of the type of the wall cases, and nine table cases. Of these 

 specimens four hundred and seventy-one are polished marbles and 

 decorative stones. These consist chiefly of polished slabs either 9x16 

 inches or 12 x 18 inches in size, although material both larger and 

 smaller is included. This collection occupies four of the wall and 

 center cases and four of the table cases. American marbles fill three 

 cases, Norwegian one-half case, English and Irish one and one-half 

 cases, Greek and Italian one case, and French two cases. Of other 

 decorative stones verte antique occupies one wall case, and Mexican 

 onyx and alabaster two cases. The four table cases are occupied by 

 miscellaneous polished marbles, verte antique, Mexican onyx and 

 other decorative stones in various ornamental forms. The remaining 

 five table cases are occupied by the collection of building stones con- 

 sisting of two hundred and forty four-inch cubes. Of these, granites, 

 limestones, and marbles each occupy one case, and sandstones, includ- 

 ing lavas, occupy two cases. Hall 68, containing the collection of 

 clays, soils, etc., has also been completely recased and reinstalled. The 

 cases consist of four wall cases and sixteen table cases. Of these the 

 clay collection occupies twelve table cases and half a wall case, the soil 

 collection four table cases and one wall case, sands and cements one 

 wall case, clay-like minerals half a wall case, and mineral pigments one 

 case. The clay collection is divided into two parts, a synoptic and a 

 general collection. Of these the synoptic collection is installed in four 

 table cases, upon the floors of which diagrams show the derivation and 

 relationships of the various classes of clays. In proper position upon 

 the diagrams are placed specimens of each group of clays. This classi- 

 fication separates the clays into twenty-eight groups, the numbers of 

 which are similar in origin and industrial application. The general 

 collection of clays, numbering at present five hundred and fifty speci- 



