REPORT OF NATIONAL MUSEUM, 1919. 109 



Prof. T. D. A. Cockerell has completed a monograph on fossil 

 insects from the oil-bearing shales of the west, based on material 

 belonging to the Museum. The chief value of the work lies in the 

 fact that insects are the most characteristic fossils of these oil shales. 



Dr. Edwin Kirk, paleontologist of the United States Geological 

 Surrey, with an office in the Museum building, has aided in the care 

 of the collections by assembling all Paleozoic faunas from the west- 

 ern United States and Alaska and assiuning responsibility for their 

 preservation. His researches in Alaska during the past year resulted 

 in an unrivaled collection from that region. 



In the section of vertebrate paleontology the free mount of the 

 skeleton of Dimetrodon gigas was finished and placed on exhibition. 

 Work was resumed on the mount of Brontothenumv TiatcTieH^ tempo- 

 rarily laid aside last year, and considerable time has been devoted to 

 cleaning, repairing, and restoring Titanotherium skulls, 15 of which 

 were completed. These will be placed on exhibition as soon as 

 proper case facilities are provided. A skeleton of the primitive 

 Permian reptile Dmdectes 'phaseolinu^ Cope; a skull, lower jaws, 

 and other parts of the skeleton of an extinct, long-snouted porpoise 

 from Chesapeake Beach; and the type specimen of Delphinodon 

 dividum True have also been prepared, the last two having been 

 mounted for exhibition. The skeleton of the huge swimming reptile 

 Tylosaurus^ recently acquired, is also in course of preparation. 



The preparation of fragmentary^ vertebrate remains designed or 

 suited only for the study series must necessarily be secondary to that 

 of exhibition material. Considerable progress has been made along 

 these lines, particularly with the recently acquired Dimetrodon ma- 

 terial from Texas and the dinosaurian from Canon City, Colorado, 

 Progress has also been made in the preparation of the Cumberland 

 Cave collections, 12 specimens of the fossil peccary Platygonus and 

 several specimens of carnivores, including four fairly good skulls 

 and other pieces representing three new species of the dog family, 

 having been cleaned sufficiently for study. Mr. Gidley's studies of 

 the fossil peccaries from this deposit have been completed and that 

 of the carnivores from the same source begun. Mr. Gidley has also 

 published a brief paper entitled Significance of divergence of the 

 first digit in the primitive mammalian foot. Some progress was 

 also made in continuation of the work on the Fort Union mammals 

 and on the combined investigation of the rodents, living and extinct, 

 the joint work of Mr. Gidley and Mr. Grerritt Miller. 



Mr. C. W. Gilmore has transmitted to the United States Geological 

 Survey for publication an extended paper on the reptilian faunas 

 of the Torrejon, Puerco, and underlying Cretaceous formations of 

 San Juan County, New Mexico. He has also submitted a short paper 

 on the newly mounted skeleton of Dimetrodon gigas, with notes on 



