THE BRYOLOGIST 



Vol. XVI July 1913 No. 4 



NOTES ON NORTH AMERICAN HEPATIGAE. IV 



Alexander W. Evans 



With the exception of the new species of Cololejeunea from Florida the 

 Hepaticae discussed in the present paper are all more or less well known. The 

 first species is introduced to call attention to a question of synonymy, the others 

 to record extensions of geographical distribution. It is perhaps worthy of note 

 that twenty-nine species of Lejeuneae, including the two additions mentioned 

 below, are now known from Florida. Since the writer published his synopsis 

 of the Lejeuneae of the United States and Canada,^ eleven years ago, thirteen 

 species of this group have been added to the flora of the state, and still further 

 additions may reasonably be expected. 



I. RiCCIA ARVENSIS Aust. 



The writer recently brought out the fact that Riccia bifurca, as understood 

 by recent European authors, was very closely related to the North American 

 R. arvensis? It was intimated, indeed, that the two species were probably 

 identical, although no definite conclusion was reached in the absence of living 

 material of R. bifurca for comparison. Such material has since become avail- 

 able. It was collected by W. E. Nicholson near Hastings, Sussex, England, and 

 sent to Miss Lorenz at Hartford. A portion of this material was kindly for- 

 warded to New Haven and compared with typical specimens of R. arvensis. It 

 proved beyond a doubt that the two species were synonyms. On the basis 

 of this identity the writer again suggests that the species should bear the name 

 R. arvensis Aust., in spite of the fact that R. bifurca Hoffm. was published in 

 1795 while Austin's name dates from 1869. The reasons for this suggestion 

 have already been stated at length. They are based upon the following facts: 

 first, that no one knows positively which species or group of species formed the 

 basis for Hoffmann's description; second, that R. bifurca, as at present under- 

 stood, dates from 1898, when Heeg definitely restricted the application of the 

 name; third, that, in our ignorance of Hoffmann's type, there is no convincing 

 evidence that R. bifurca Heeg is identical with, or included under, R. bifurca 

 Hoffm.; and fourth, that Austin's R. arvensis was clearly described and definitely 

 understood long before the publication of Heeg's paper. If this suggestion is 

 adopted the name R. bifurca will disappear from the literature as the accepted 

 name of a recognized species. 



1 Mem. Torrey Club 8: 113-183. pl- 16-22. 1902. 



2 Rhodora 14: 3. 19 12. 



The March number of The Bryologist was pubUshed March 20th; the May number, May 23d, 

 1913. 



