78 Rhodora [May 



Y devexum, o flaccidum, and e pygmaeum, but acknowledging 

 their unstable character. Under the first of these he recognized 

 subdivisions of a lower rank (forms and sub-forms), giving them the 

 names J- 1 commune, a 1*. fuseum and a 2 don gat inn; under the 

 second he recognized the subdivisions £ 1 laxius, £ 2 innovans, 

 § 2* julaceum and /3 3 gemmiparum; but under the others, y, 8 

 and e, he distinguished no lower subdivisions. As synonyms of 

 certain of these subdivisions he cited the following species, which 

 had been either published by earlier writers or distributed in exsic- 

 catae under manuscript names. Jungermannia tricrenata Wahlenb. 

 (181 1), under a 1 ; ./. triangularis Schleich. (1805), nomen nudum, 

 under a 1 and a ]*; J. deflexa Mart. (1817), under a 1*; Pleuro- 

 schisma flaccidum Dumort. (1831), under $ I; P. parvulum Dumort. 

 (1831), under @ 2; and Jungermannia flaccida Schleich. (1821), 

 nomen nudum, under 3. He chose the name deflezum for the species, 

 rather than tricrenatum, on account of an inaccuracy in the original 

 description of Jungermannia tricrenata; but of course this would not 

 now be considered a sufficient reason for invalidating Wahlenberg's 

 species. 



Nees von Esenbeck 's subdivisions were taken over bodily in the 

 Synopsis Hepaticarum (1845), where the species appears under the 

 name Mastigobryum deflexum Nees. They were adopted also by 

 Lindenberg and Gottsche in their monograph of Mastigobryum, 1 

 published a few years later, the subdivisions ot 1, a 2, P 1, P 2*, 

 T, 8 and e being separately illustrated on their plate. The more 

 typical condition of the species, as described above, is clearly shown 

 by /. 1~4, which illustrate a 1 tricrenatum commune. Subsequent 

 writers have either ignored Nees von Esenbeck 's subdivisions al- 

 together or have used his names very sparingly. 



For many years the species continued to be known by the name 

 Mastigobryum deflexum, but this name has gradually been super- 

 seded by other names. By those who recognize the genera of S. F. 

 Gray the name Bazzania tricrenata is usually employed. In 1875, 

 however, Lindberg 2 revived for the species the old specific name 

 triangularis of Schleicher, forming the combination B. triangularis 

 (Schleich) Lindb. He apparently dated the name from the year 

 1805, when Schleicher distributed specimens of Jungermannia 



1 Spec. Hepat. Mastigobryum 108. pi. 18. 1851. 

 Acta Soc. Sci. Fenn. 10: 499. 1875. 



