104 Field Columbian Museum — Reports, Vol. II. 



wood mahogany. In rearranging the paleontological collections the 

 specimens were so grouped as to distinguish the three great eras. Thus 

 all of the fossils of the Palezoic era are now exhibited in Hall 35, those 

 of the Mesozoic era in Halls 36 and 59 and those of the Cenozoic era in 

 Halls 59, 60 and 61. At the same time all form a consecutive series 

 from the earliest to the latest. Besides the cases in which the 

 specimens are arranged in stratigraphical order, and which form the 

 bulk of the collection, a collection occupying two cases has been 

 prepared which affords a comparison of ancient and living forms while 

 another collection illustrating methods, of fossilization occupies a 

 single case. A series of bromide enlargements illustrating restora- 

 tions of ancient animals has been framed and placed in the cases. 

 An ideal Carboniferous landscape painted in oil was made by 

 the Museum artists and is exhibited in connection with the fos- 

 sils of that period. The painting is 8x4 feet in size. The large 

 skeletons and specimens having individual floor mounts were 

 moved to positions corresponding with the new classification 

 and new bases were made for them. Three of the large Dinosaur 

 bones have been placed upon floor mounts. The work of cleaning 

 from the matrix the bones of the large dinosaur individual obtained 

 by the expedition of 1901 was pushed as rapidly as the available 

 force would permit. The following portions of this skeleton are at 

 present cleaned and upon exhibition: 23 caudal vertebras (in series), 

 15 chevrons, 3 dorsal vertebras, 2 pubes, 2 ischia, 1 femur and 

 1 ilium. In addition considerable work has been done in the paleon- 

 tological laboratory in remounting and reassembling vertebrate fossils 

 on hand since the opening of the Museum which had never been 

 properly prepared. A careful revision of the identification and 

 labeling of the invertebrate fossils was made by Mr. Slocom of the 

 Department and at the same time any needed cleaning and restora- 

 tion of the specimens was performed. The result of this extensive and 

 detailed labor has been to greatly increase the value and improve the 

 appearance of the collections. As the force of preparators in paleon- 

 tology was increased and more room was needed for their work, the 

 Curator's office and the paleontological laboratory were exchanged in 

 place. The laboratory thus obtained was fitted with storage racks, 

 sink, closet and revolving work tables, and sliding overhead curtains 

 were provided to regulate the light. In the room now occupied as the 

 Curator's office a side window was cut, the room recalcimined, a closet 

 built, and a transfer of bookcases made. The collection of relief maps 

 formerly occupying Halls 60 and 61 was transferred to Halls 75 and 





