13 This portion of the collection contains specimens derived originally from the unmounted non-exsiccati materials described in the third part of the 1857 bequest. A Catalogue of the Unmounted Materials [of the] Bailey Collection in the Boston Society of Natural History, which was produced in 1860, has been the sole measure of materials appropriate to this part of the Collection. This Catalogue was initially the property of the Society, but by 1938 and by unknown means it had passed into the possession of Clarence A. Cheever, an amateur Massachusetts diatomist. It lists 705 samples, primarily infusoria, representing an unknown proportion of the original amount of material, but also contains notes by Cheever indicating that many of the samples were either missing or contained so little material as to be useless. I have found in the Farlow Herbarium a loosely grouped collection of 100 vials designated collectively as "Bailey Collection ex B.S.N.H." These vials were apparently the gift of Cheever in 1941 or 1943 along with the 1860 Catalogue, but these vials have plastic screw caps indicating they are not the original containers of Bailey eventhough the material inside may be his. However, because none of these vials bears any identifying notes or numbers and because I have been unable to determine how Cheever secured them, I have not included them in this accounting of the collection. Also, in 1976, I found loose among miscellaneous papers pertaining to the diatom collections in the Farlow Herbarium an undated unsigned three- page note entitled "Bailey Collection. Unmounted Materials." describing a collection of boxes, dry mounts, etc. contained in a small cabinet; the materials were in accord with entries in the 1860 Catalogue. Because the note makes reference to the cabinet being associated with several volumes of Bailey's letters and notes, which are still in the possession of the Boston Society of Natural History (now Boston's Museum of Science),