The collection of fishes made by Captain John M. Dow of the Panama Railroad Company represents one of the earliest and most important collection of fishes from the Pacific coast of Central America. There are 133 entries in the Division of Fishes catalog attributed to Dow, of which 81 can currently be located. These represent some 61 species and include 29 types. The material is summarized, catalog numbers and sizes are given, and the current condition of each specimen is assessed. Missing specimens are summarized, with as much information on each as is available. Photographs of 21 of the type specimens are included.