86 REPORT OF THE SECRETARY. 



Smtveed.s. — Aquatic plants were represented by seaweeds, a full series of the prin- 

 cipal American types of which were exhibited in two cases on the central aisle. 



Department of Geology. — The exhibit of this department was })lanned and 

 arranged l)y Dr. (leorge P. Merrill, head curator, assisti'd by the scientific staff. 



The exhiV)it was planned and arranged to convey an idea to the i)ublic of the 

 scope of the department. To this end the space was divided in ecjual ])ortions 

 between the divisions of systematic geology, mineralogy, paleontology, and ])aleo- 

 botany. 



Dirmon of i^j/xtciiKdic (ind applied geology. — In this division were two cases filled 

 with examples of cave deposits and concretionary structures, and live cases contain- 

 ing minerals, rocks, and ores of economic value, including a characteristic series of 

 the iron ores of the United States, and a systematic series of ores of the minor metals, 

 including those of mercury, nickel, and cobalt, antimony, bismuth, and others of the 

 rarer metals. Also a collection of noumetallic minerals of economic importance, 

 including various salts u.sed in chemical manufacture, abrasives, fictile materials, 

 asbestus, mica, mineral pigments, graphite, coals, and other natural hydrocarbon 

 compounds. 



Dirmon of ininiralogii. — The exhibit of this division treated of the systematic 

 arrangement and chemical cla-isitication of the several representatives of the mineral 

 kingdom. 



The series was grouj)ed under two clas.ses — elements and compounds of elements. 

 The compounds of the elements were further divided in accordance with chemical 

 laws and grouped imder certain prominent types according to, and which take their 

 names from, their more negative constituents, as follows: Compounds of the halogens, 

 fluorides, chlorides, bnimides, and iodides; compounds of sul2)hur, selenium, and 

 tellurimn; al.'^o arsenic, antimony, and bismuth, including sulphides, selenides, and 

 telhirides; arsenides, antimonides, and bismuthides, sulpharsenides, and sulphanti- 

 monides; also sulphosalts, oxygen comi)ounds, including f)xidesand the oxygen salts, 

 borates, aluminates, chromitesferrites, nianganitcs, selenitcs and tellurites, carbonates 

 and tantalates, nitrates, vanadates, phosphates, arsenates, selenates and tellurates, 

 chromates; molybates, tungstates, iodates, and uranadates. Each of these gnjups was 

 preceded by a descrij)tive label giving the name of the type and a brief description 

 of its more prominent character. Following the'descriptive label, arranged in order 

 from left to right, were several representatives of the type selected, so far as possible, 

 to illustrate the character of the group as a whole. 



Section of invertehr(de fossils. — In one case was shown the largest American ammonites, 

 a group of chambered shells related to the living Pearly Nautilus. Another case was 

 devoted to crinoids, a group of animals related to the starfishes. The following two 

 cases were occupied by trilobites, crustaceous animals which became extinct shortly 

 after the great coal series of the Mississippi Valley had been formed. Still another 

 case was devoted to lampshells, or bra<;hiopods. The interior structure of some of 

 these shells was illustrated by models showing, among the characters, the spiral 

 skeleton for the support of the arms. 



The crinoids, trilobites, and brachioi)ods were arranged in sytematic order, and 

 the series of specimens rei:)resenting each general group was preceded by a descrip- 

 tive label. All these fossils were mounted on uniform buff-colored encaustic floor 

 tiles, a method of installation recently introduced into the National ]Museiim. 



Section of vertebrate fossils. — In this section was shown a series of specimens of 

 some of the earlier forms of fishes, and a series of teeth and spines of Carboniferous 

 sharks. These two series were accompanied by illustrations showing the forms of 

 fishes when restored, and the position of the spines and their relations to the fins. 

 Specimens of the fishes from the Eocene formation of Green River and of Mosasaur 

 reptiles from the chalk formation of western Kansas were also exhibited. 



The Smithsonian Institution, the National Museum and its departments of anthro- 



