In 1910 he joined the Zoological and Anthropological section of the Indian Museum and when the organization was converted in 1916 to the Zoological Survey of India, he became Superintendent and took up the study of crustaceans to continue work started by James Wood-Mason and Alfred William Alcock. He spent fourteen years in India during which he published seventeen papers on the decapods in the Indian Museum. In 1918 he made a trip to Baluchistan along with Thomas Nelson Annandale. Other expeditions were made to the Andaman Islands, the Garo Hills and Rameshwaram. In 1913 he married Agnes Green, daughter of Reverend William Spotswood Green who was the first to climb Mount Cook in New Zealand. In 1910 he became a Fellow of Calcutta University and a Fellow of the Asiatic Society. In 1924 he returned to Ireland to become the first director of research in the Discovery Investigations.