zoologist and naturalist who, as curator of zoology at the Peabody Museum of Natural History at Yale University, developed one of the largest, most valuable zoological collections in the United States.

From 1871 to 1887, while he was in charge of scientific explorations by the United States Commission of Fish and Fisheries, Verrill found and described hundreds of new marine specimens. He specialized in invertebrates, especially worms, mollusks, corals, sponges, and starfishes, and made important technical improvements in the equipment used for collecting specimens. His expeditions took him to the Atlantic and Pacific coasts of North America and to Hawaii and Central America; many of his more than 300 papers became standard references.

Verrill studied at Harvard, where he was an assistant to Louis Agassiz (1860–64). He was professor of zoology at Yale (1864–1907), curator of zoology at the Peabody Museum of Natural History (1865–1910), nonresident professor of comparative anatomy and entomology at the University of Wisconsin, Madison (1868–70), and an instructor in geology at Yale (1870–94).