Curtis Gates Lloyd was a prominent American mycologist active from the late 1880s until his death in 1926. The C. G. Lloyd Mycological Collection was transferred to the United States Department of Agriculture Mycology Collections in 1927 and is currently housed at the USDA Agricultural Research Service U.S. National Fungus Collections (Herbarium BPI) in Beltsville, MD. The Lloyd Collection is likely the largest fungal herbarium ever assembled by a single person and consists of approximately 59,000 specimens. These cards represent the original index to the Lloyd Collection prepared in 1928 and include valuable specimen information and annotations.