university, most helpfully suggested an inspection of the fascinating 

 floating-marsh environment fringing Lake Hatch south of Houma, 

 Louisiana, and Mr. Orton safely conducted the party across this 

 treacherous flotant. While working at Tulane University Curator 

 Zangerl with the help of Curator Richardson studied the shield 

 variations in a large portion of the splendid series of turtles of the 

 Gulf Coast states collected by Dr. Cagle and his associates. 



In pursuance of their interest in black shales, Curator Zangerl 

 and Curator Richardson investigated a deposit of this type in 

 a Mississippian sequence of limestones near Oolitic, Indiana. The 

 locality and occurrence of the shale were called to their attention 

 by Dr. Harold R. Wanless, of the University of Illinois. On their 

 return journey to the Museum they stopped at Urbana and discussed 

 the subject at length with him. Curator Richardson also devoted 

 some time to further his study of Coal Age fossil-insects and made 

 several excursions to the Northern Illinois Coal Company's strip 

 mines in the vicinity of Braidwood and Coal City, Illinois. On one 

 of these trips he discovered a locality that had apparently escaped 

 the attention of the numerous avid collectors of these fossils and 

 found there several rare fossils, including a complete cockroach, an 

 insect wing, a spiderlike arachnid, and an eurypterid. 



William D. Turnbull, Assistant Curator of Fossil Mammals, 

 revised and expanded his manuscript on a Late Cretaceous mar- 

 supial from the Lance formation of Wyoming and continued his 

 studies of the mammalian masticatory apparatus. He also spent 

 some time in planning the paleontological expedition to the Washa- 

 kie Basin of southwestern Wyoming, on which he was accompanied 

 by Orville L. Gilpin, Chief Preparator of Fossils. They were in the 

 field for two months, during which they made a representative 

 collection from two levels, the Lower and Upper Washakie. Late 

 in the fall, Turnbull and Preparator Bruce Erickson investigated 

 the remains of well-preserved but somewhat incomplete skeletal 

 elements of a mastodon found in a drained peat-bog in northern 

 Indiana. Search for the missing elements was without success. 



Dr. Robert H. Denison, Curator of Fossil Fishes, continued his 

 studies of the Devonian armored fishes known as arthrodires. This 

 work, though based primarily on our collections from Utah, has 

 included a review of all known members of this group, particularly 

 the earlier ones. The Utah specimens have been prepared by the 

 use of acetic acid, a slow but in this case a very satisfactory method 

 of removing the limestone matrix. In June he visited the long- 

 abandoned Rockport quarry in the Middle Devonian rocks near 

 Alpena, Michigan, where he collected a number of arthrodires. 



53 



