of the Museum's collection of meteorites progressed most satis- 

 factorily. Every specimen in the collection was weighed and all 

 pertinent data, including important references, were checked and 

 rechecked. This tedious but essential task was accomplished with 

 creditable thoroughness by Henry Horback, Assistant in Geology. 



While conducting field work in Central America, Chief Curator 

 Roy made an important observation of volcanism at Volcan Izalco 

 in El Salvador. Last year, on February 28, Izalco had the most 

 violent eruption in its history, during which it literally "blew its 

 top" and split its northeast flank, pouring forth a vast flow of lava, 

 ashes, and cinders. This year, in September, Dr. Roy found the 

 volcano appearing as though nothing had happened — it had regained 

 its original shape and height by pouring ashes and cinders over the 

 damaged area. Dr. Roy believes that Izalco's action typifies that 

 of all other volcanoes of its kind — that damages caused by eruptions 

 are soon repaired (see illustrations). 



Accessions— Geology 



A large and important collection of Lower Devonian fishes was 

 presented by Dr. J. Ernest Carman, Professor Emeritus of Geology 

 at Ohio State University. This material, which was collected more 

 than thirty years ago in a quarry in northwestern Ohio, includes 

 numerous specimens of the ostracoderm Pteraspis, known elsewhere 

 in North America only from Nova Scotia, and other primitive 

 ostracoderm not yet determined as to genus. Our collection of the 

 rare Pennsylvanian fishes from the Mazon Creek area of Illinois 

 was augmented by several sharks, coelacanths, and palaeoniscoids 

 from the Walker Museum Collection of the University of Chicago 

 (accessioned 1947) and by an exceptionally well-preserved specimen 

 of Elonichthys donated by Dr. and Mrs. Whitfield, Associates. 



A notable addition to the fossil-mammal collections was a set of 

 casts of the famed South African Australopithecin materials. The 

 casts were made at the Museum from the original specimens brought 

 by Dr. J. T. Robinson, of the Transvaal Museum, Pretoria, to the 

 Chicago meetings of the American Association of Physical Anthro- 

 pologists. A fine lot of fossil-mammal material (microfauna) from 

 west Australia was donated by Dr. Ernest Lundelius, of California 

 Institute of Technology, supplemented by a smaller but valuable 

 collection (macrofauna) from east Australia donated by Wendell 

 B. Swanson, of Chicago. Both of these collections are from the late 

 and post Pleistocene epoch. 



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