Jan., 1920. Annual Report of the Director. 



317 



only for the amoitnt of the material contained in it, but also for its well- 

 prepared condition. The collection consists of two principal series, 

 one chiefly of remains of mastodons obtained in Minooka, Illinois, and 

 the other of specimens of mosasaurs from Kansas. The mastodon 

 material includes remains of eight individuals, which range in age from 

 a young calf to an adult. Of one large, adult male, portions of the 

 skull, complete lower jaws, many limb bones, vertebrae, ribs and foot 

 bones are preserved, as well as a tusk nine feet in length, probably the 

 largest tusk of an animal of this species ever found. The other individu- 

 als of this series are represented by various skeletal parts, an especially 

 important feature being that the entire tooth development of the masto- 

 don is shown by specimens ranging from the first milk teeth to the 

 ponderous, grinding molars of the male adult. Of the collection il- 

 lustrating mosasaurs, the most important feature is two nearly perfect 

 skulls, one two feet, the other eighteen inches in length which have been 

 carefully excavated from their matrix and motmted free. These display 

 in remarkable completeness the characters of the heads of these extinct 

 "sea serpents." Come vertebrae are also associated with these skulls. 

 A large jaw of a Coltmabian mammoth and a head of the fossil fish, 

 Gillicus, also are included in the collection. Three complete individuals 

 from the meteorite fall which occiured at Cumberland Falls, Kentucky, 

 in April of this year, have been added to the meteorite collection, one 

 being the gift of Mr. W. R. Jillson. The meteorites of this fall are of 

 peculiar interest on accoimt of their unique composition and structure. 

 Of the meteorites of Richardton, North Dakota, which fell Jtme 30, 191 8, 

 four individuals, aggregating about ten pounds in weight, were ob- 

 tained, partly by ptirchase and partly by exchange with Professor T. T. 

 Quirke. By exchange with the British Museum, representative speci- 

 mens of the Baroti, Kuttipuram and Warbreccan meteorites were 

 sectu'ed. A specimen of amethyst showing remarkable distribution of 

 color, and two valuable crystals of scheelite were presented by Mr. W. J. 

 Chalmers as additions to the Chalmers crystal collection. Several 

 specimens of high-grade gold ore from Cripple Creek, Colorado, showing 

 considerable free gold, were presented with other material by Mrs. G. 

 Mace, and a collection containing, among other specimens, several 

 minerals used in optical work was received by gift from Dr. Geo. M. 

 Gill. By exchange with Prof. M. E. Kleckner, about one hundred speci- 

 mens of crystallized celestite, fluorite, calcite and sphalerite from locali- 

 ties in Ohio and Michigan and of forms previously imrepresented in the 

 Museinn were obtained. Six specimens of typical Barbadoes earth 

 and one of globigerina marl from the Barbadoes Islands were obtained 

 by exchange with the University of Iowa. These illustrate deposits of 



