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ing this long-lost species. I did not find it at just those points, but at Athens, 

 Georgia, in the. same general region, I did find what I took to be it and so an- 

 nounced the rediscovery of the species. Since that time, however, I have felt 

 that there were difficulties in the way of distinguishing the Georgian Riccia Bey- 

 richiana from R. Lescuriana, which was described from New Jersey in 1869 and 

 has since been reported from as far south as Florida, as far west as California, 

 and has been alleged to occur in Europe also. 



At the time of examining the original material of Riccia Beyrichiana, the 

 thallus seemed to me so much smaller than that of R. Lescuriana as I then knew 

 it, while the spores were so much larger and so much more opaque, that it hardly 

 occurred to me that the two were closely related. Stephani, in his somewhat 

 artificial arrangement of the species in his Species Hepaticarum, had placed them 

 fifteen numbers apart. He had, by the way, described the thallus-margins of 

 R. Lescuriana (name modified to " Lesquereuxii'') as naked, although Austin's 

 original diagnosis had stated that they were ciliate, and, on the other hand, he 

 had attributed cilia to the thallus-margins of R. Beyrichiana, even though the 

 original description of this species had implied that they were naked. The facts 

 are that the original specimen of Riccia Beyrichiana shows a few inconspicuous 

 cilia and authentic specimens of R. Lescuriana show more obvious ones. A 

 study of a considerable series of living American specimens referred to R. Les- 

 curiana indicates that the thallus-margins normally and usually show a few cilia, 

 but that, as in most ciliate-margined species, the cilia are occasionally wanting 

 or deciduous or are so few and small as to be easily overlooked. In the matter 

 of the size of the thallus it is to be noted that, although the type of Riccia Bey- 

 richiana seemed to me a much smaller plant than R. Lescuriana, Stephani, who 

 also saw authentic material of R. Beyrichiana, makes it out to have at least a 

 longer thallus (max. 10 mm. vs. max. 7 mm.) than does R. Lescuriana. In the 

 matter of the size of the spores, one sometimes finds in Riccia a good deal of 

 variation in the spores from a single capsule and in spores from different capsules 

 on a single plant. And in this matter of size of spores, specimens of undoubted 

 Riccia Lescuriana from Florida and California make a close approach to the 

 type of R. Beyrichiana from Georgia. And the same may be said in regard to 

 the opacity of the older spores. More constant and reliable than the size of 

 the spores as a specific character are their surface markings, and in this respect 

 the spores of the type of R. Beyrichiana are essentially like those of authentic 

 specimens of R. Lescuriana, that is to say, the outer face of the spore is strongly 

 areolate with large meshes, while the inner faces are nearly smooth or are at 

 most only faintly and imperfectly areolate. When all of the supposedly dis- 

 tinctive characters of Riccia Beyrichiana and R. Lescuriana are compared, in a 

 good series of specimens from various localities, one, I think, is forced to the 

 conclusion that they do not offer a safe and satisfactory basis for specific dis- 

 tinctions. The name of the species then becomes Riccia Beyrichiana Hampe, 

 a name that was published thirty one years earlier than Riccia Lescuriana Aust 

 The species evidently has a wide range in North America. Its most northeastern 

 station, so far as now known, is at Northampton, Massachusetts, where it has 



