Geological Relief Models 57 



major portion of the western half of the hall was definitely 

 set apart for the series of fossils and other material illustrat- 

 ing historical and stratigraphical geology, and the correspond- 

 ing portion of the eastern side of the hall was assigned to the 

 biological phase of palaeontology. The alteration of the up- 

 right cases called for by the plan adopted was begun in May 

 and is practically completed, so far as the reception of the 

 historical and biological exhibits is concerned. These cases 

 have been adapted for the installation of a scheme of internal 

 lighting that promises highly satisfactory results. 



The exhibition series of Pelecypoda as selected by Dr. Reeds 

 is being checked up, labeled and arranged by Dr. Maury. This 

 has called for an immense amount of time-consuming labor 

 in the verification and changing of determinations, but the 

 work has advanced so far that the specimens for more than 

 three-fourths of the alcove devoted to this branch of palae- 

 ontology are in place, and this section of the hall will be com- 

 pleted early in 1919. The reference data which Dr. Maury 

 has prepared concerning each species have been typewritten on 

 slips of paper which have been pasted on the backs of the ex- 

 hibition tablets, and a typewritten exhibition label has been 

 attached to each tablet. 



Dr. O'Connell has made a good start in arranging the 

 Cephalopoda for the exhibition biological series. 



The exhibit of Bryozoa which was prepared last year by Dr. 

 J. J. Galloway has been installed in its permanent position. 



The core for a model of a section of the Grand Canyon, 



which was begun under the direction of Assistant Curator 



Reeds in March, 191 7, was about four-fifths 



Topo-geo- finished when Mr. Hill joined the army in May, 



Relief I918 ' This was com P leted b y Mr - Latzko and 



Models placed in the hands of the Morgan Brothers Com- 



pany of this city for the modeling of the surface 

 and the preparation of the painted background. During the 

 fall Mr. Lester Morgan made a special visit to the Canyon for 

 securing sketches and other data for his work, and it is reason- 

 ably expected that the finished model will be installed during 

 January, 1919. This model will form a most attractive and 



