This volume contains Rehn's notes from five Orthoptera surveys in North America between 1939 and 1946. The first part of this volume (pages 1 to 80) constitutes Rehn's field journal from his 1939 "Southern Appalachian-Ozarks Survey," from July 29th to September 9th. Rehn's title of this survey is misleading, in that the survey included exploration throughout the southern and southwestern United States. During this portion of the survey, Rehn re-visited many of the locations from his 1937 Orthoptera survey (Volume 22).

Pages 82 to 174 of this volume contain Rehn's notes from his 1941 "Northwestern Orthoptera Survey," from July 11th to August 8th. The party reached their campground in Nebraska's Wild Cat Hills on July 16th. The survey continued north-west from Nebraska to Washington, moving through various nature preserves, such as Yellowstone National Park, Kaniksu National Forest, and Ranier National Park. From Washington, the survey continued south through Oregon and California, then north-east through Nevada, New Mexico, Utah, and Colorado. The last mention of species names is on August 28th, between Steamboat Springs and Boulder Colorado.

Pages 175 to 191 contain Rehn's notes from his brief 1942 "Kentucky - Tennessee" survey from the 9th to the 22nd of August. The party arrived at Ashland, Kentucky on August 11th, and moved south-west toward Kentucky. They collected in the vicinity of what is now the Daniel Boone National Forest, Cumberland Lake, and the Big South Fork National Recreation Area in Kentucky and Tennessee. They then traveled alongside the Cumberland River towards Nashville, Tennessee. At Nashville, the party turned north to Bowling Green, Kentucky, and shortly thereafter, they moved north-east to Nicholasville. Collecting ended on August 16th.

Pages 193 to 224 contain Rehn's notes from his 1945 east coast Orthoptera survey, from August 3rd to September 7th. Rehn's title for this survey, as it appears in this volume, is "To Fla. - Return." Although Rehn collected along his route to and from Florida, he seems to have concentrated his collecting in the vicinity of Coral Gables, Florida (August 11 to 28), with day trips to Florida City and Long Key. Journal entries from August 10th, 14th and 15th memorialize Victory over Japan Day.

Pages 225 to 257 contain Rehn's notes from his 1946 "Southern Interior" survey, from August 15th to September 3rd. During this survey Rehn returned to many of the locations he visited previously during his 1942 survey. This survey included locations in West Virginia, Kentucky, Tennessee, North Carolina, and Virginia.

The last page of this journal (page 300) contains information regarding six 1941 Orthoptera collecting stations.