Complex sentence: He gave much of his attention to geology, but he is more especially distinguished for his researches on the natural history of India, and as the author of "The Land and Freshwater Mollusca of India" (1882-1887).
Split into simpler sentences: He gave much of his attention to geology, but he is more especially distinguished for his researches on the natural history of India. He is recognized as a malacologist and was the author of "The Land and Freshwater Mollusca of India" (1882-1887).