His field work provided a steady supply of new specimens for study, dissection, and illustration, and a seemingly endless array of new species to name. Pilsbry named 5680 organisms; a full list was published in a 218-page volume. Pilsbry performed extensive amounts of field work, and was clearly an expert in dealing with the outdoors, no matter the conditions. He collected mollusks over virtually the entire United States, and in an atlas of countries: Argentina, Australia, Bahamas, Cocos Islands, Cuba, Galapagos Islands, Guatemala, Marquesas Islands, Mexico, Panama, Peru, and other locations as well. His intellectual reach extended even further, through joint efforts with other workers: especially notably Africa with Joseph Bequaert and the Japanese region with Yoichiro Hirase.