The fonds reflects the scientific and literary outreach activities of the Montreal Natural History Society over the course of its existence and contains correspondence, minutes, financial records, council and committee reports, membership lists, donation lists, catalogues of holdings, newspaper clippings, lecture advertisements and weather maps. In addition, the fonds includes reference material to other societies and information regarding the publication and creation of the Canadian Naturalist and Quarterly Journal of Science, Canadian Naturalist and Geologist and the Canadian Record of Science.

The fonds is composed of the following series: 1) Accounting Records (1860-1917); 2) Administrative Records (1833-1887); 3) Catalogues (ca.1829-ca.1925); 4) Correspondence (1871-1896 with gaps); 5) Essays and Lectures (1829-1852); 6) Minutes (1827-1832,1844-1923); 7) Montreal Microscopical Society (1884-1906); 8) Reports (1828-1881 with gaps); 9) Weather Maps (1895-1897).

Most of the collection consists of Carpenter's notes and drawings of shells. There are printed catalogues of shell collections from the Pacific Ocean and the Caribbean dating from 1857 to 1876. His incoming correspondence is mainly from collectors in the United States and deals with shells. It covers the period 1858-1876. The main letter writers are J.G. Cooper, a collector from San Francisco, William Dall of the Smithsonian, James Lewis of Albany, N.Y. and William Bairn of the British Museum. Some of the material deals with Carpenter's establishment of the shell collection at McGill in 1866. There are files of clippings dealing with the death of his aunt, Mary Carpenter (1787-1877) and that of his sister, also named Mary (1807-1877) who was involved in the establishment of reform schools for girls. Included are some of Carpenter's certificates and diplomas (1834-1843). As well there is a copy of a biography of Carpenter written by his brother, Russell, in 1880. The book quotes extensively from Carpenter's letters, covering not only his years in the ministry but also his travels in the United states prior to the Civil War. As well there are interesting details of life in Montreal from 1865-1877 .

The fonds contains two sketchbooks of coloured sketches and shows William Arthur Johnson's activities in natural sciences and microscope work.

Shaw's papers include memoranda, notebooks and letters mainly on natural history. There are also annual reports of the Montréal chapter of the Nicholas Agassiz Association.