Herein as a preface to Jukar's ongoing comprehensive systematic review, we introduce the fossil vertebrate collection made by G. Edward Lewis in 1932 as part of the Yale-North India Expedition to British India, and briefly discuss its historical and scientific significance. The collection, which consists of approximately 1,300 specimens collected from 106 sites, was made 100 years after the first fossils were reported by Europeans in the Siwalik deposits of the Indian subcontinent, and includes several important specimens, most notably fossil primates. Studies of the fossils collected by Lewis on this 1932 expedition have had a substantial and long-lasting influence on Siwalik paleontology, and motivated much subsequent work in this region by both western and local Indian and Pakistani researchers. Studies of primate specimens collected and first described by Lewis have also heavily influenced the field of paleoanthropology and debates surrounding the origin of our species.