[image:17703 align=left hspace=0.5]Several species of Gyrophora (as G. proboscidea β arctica, G. hyperborea, G. Pennsylvanica, and G. Muhlenbergii) are employed by the hunters of the Arctic regions of America as articles of food, under the name of tripe de roche. All four species were eaten by Captain Franklin and his companions in 1821, when suffering great privations in America; and to its use may their preservation be in part ascribed [Franklin, Narrative of a Journey ot the Shores of the Polar Sea, 1823.]. But, not having the means of extracting the bitter principle, these lichens proved noxious to several of the party, producing severe bowel complaints.
The Elements of Materia Medica and Therapeutics, Vol. II, 3th American ed., was written by Jonathan Pereira in 1853.