108 PROCEEDINGS OF THE NATIONAL MUSEUM vOL. 106 



sample and the methods used, the extent of variation in the 

 selected morphological features was determined for each form. 

 Geographic, seasonal, and host distributions were considered. 



Type material was studied at the U. S. National Museum. 

 Cotypes were borrowed from the Museum and paratypes were 

 borrowed from the Rocky ]\Iountain Laboratory. Duke University 

 material was compared with these specimens and valid names 

 were determined for the species already described. Specimens of 

 Euschdngastia species which did not occur in the collections as- 

 sembled at Duke University were studied at the U. S. National 

 Museum, or where borroAved from the Museum and the Rocky 

 Mountain Laboratory. 



Amount of rainfall and temperatures of the air, soil surface, 

 and subsoil in the Duke Forest area were obtained from a 

 station maintained by Dr. G. W. Wharton on Duke Homestead 

 Road. The temperatures were recorded continuously by a triple 

 record thermograph. On Dec. 18, 1948, the air temperature 

 recorder ceased operating. Air temperatures after that date 

 were obtained from the records of the weather station at the 

 Raleigh-Durham airport. Rainfall v/as determined by a standard 

 rain gauge. Theses in the Soils Department of Duke University 

 were consulted for moisture content of soils in the forest. Eco- 

 logical observations were obtained directly from two collectors 

 in other areas who were supplied with blank chigger ecology data 

 forms and lists of hosts from which they had sent chiggers. 



Several persons made identifications of material other than 

 chiggers. Miss Grace Glance, of the U. S. National Museum, 

 identified the Onychiurus sp. and Sinella curviseta. Host identifi- 

 cations of the Pennsylvania Mammal Survey collections were 

 made by Miss Caroline A. Heppenstall and Dr. J. K. Doutt, 

 Carnegie Museum, except for the later collections which were 

 identified in the field by the collectors. Dr. F. S. Barkalow, Jr., 

 State College, Raleigh, North Carolina, identified the hosts col- 

 lected by Mr. Ray Allison in Wake County, North Carolina. 

 Hosts trapped in Ohio and Kentucky by Mr. Woodrow Good- 

 paster, Cincinnati Museum of Natural History, were identified 

 by the collector. Dr. G. W. Wharton, Duke University, identified 

 certain mammal hosts from which he collected chiggers in, 

 Pennsylvania in July 1947. Some of the study skins made of 

 representative mammal hosts collected at Duke University were 

 identified to subspecies by Dr. David H. Johnson, U. S. 

 National Museum. Mr. Kerwin Hyland, Duke University, identi- 



