Russian-born naval surgeon and naturalist. Served on the hospital ship at Greenwich, 1832–55. Retired from medical practice in 1855. Member of several scientific societies. President of the Microscopical Society, 1848–9; of the Anthropological Institute, 1873–4. Zoological secretary of the Linnean Society of London, 1857–68. Hunterian Professor of comparative anatomy, Royal College of Surgeons of England, 1856–9; council member, 1863; member of board of examiners, 1868; president, 1871. Specialised in palaeontology and in the study of Bryozoa. FRS 1850.