To accompany a synopsis and interpretation of the North American Quaternary fossil bryophyte record published in this journal in 1976, a catalog is presented detailing the species that have been reported and their geographic and stratigraphic settings, ages, and places of publication. The bibliography contains annotations pertinent to the fossil-bearing deposits, including information on their correlation and availability of associated paleobotanical data. The catalog lists records of megascopic remains of 172 extant species of mosses in 82 genera and of five species and six genera of extant liverworts. Records are also included of seven putatively extinct species of mosses based on fossils from North America. Most of the reports are from late Wisconsinan sediments from sites in the northeastern United States and adjacent Canada. Records from older Pleistocene deposits are relatively few. The catalog is a data base for studies in Quaternary phytogeography and paleoecology.
The liverwort Hymenophyton flabellatum possesses a dendroid gametophyte with a repetitive pattern in its organization. Its morphogenesis is described. A correlated light and electron microscope (SEM and TEM) study is made of its water-conducting system. The conducting elements bear a superficial ressemblance to the tracheids of vascular plants. However, both the ultrastructure of their walls, which are perforated by small plasmodesmata-derived pores, and the absence of lignin, readily separate these cells from the tracheary elements of true vascular plants.