﻿184 Howe : New American Hepaticae 



of July and the first of August, it is probable that their submersion 



is permanent. 



The plant described above was referred at first, uncritically, 

 to Scapania undnlata and listed under that name in Erythea 

 : 49. 1896). From >S. undnlata, however, it is certainly 



very distinct in the obscurely complanate branches, in the 

 sometimes 3-ranked, often more deeply lobed, erecto-patent, 

 never .alate-carinate, leaves, with more or less squarrose tips, 

 and in the obovate rather than round-trapezoidal ventral lobes. 

 The interpolated unlobed leaves stand sometimes in about the 

 general position of dorsal or ventral lobes, but more often 

 squarely subtend the ventral surface of the stem. They can 

 doubtless be explained in some cases, from the point of view of 

 ontogeny, by the separation of the normally united lobes, but in 

 other cases this hypothesis seems to find little justification. We 

 have noticed one or two three-lohtd leaves out of hundreds exam- 

 ined and in such the complete disjunction of the most ventral lobe 

 would have thrown it nearly into the place of an underleaf. When 

 the leaf-lobes are subequal it is often difficult to distinguish between 

 the dorsal and ventral aspects of the stem, especially if further 

 confused by the presence of the supernumerary entire leaves. 

 From stems of such a character as this, however, .may spring 

 young shoots in which the leaves are regularly distichous and 

 acutely complicate, in the ordinary Scapania fashion, with the ven- 

 tral lobes twice the size of the dorsal. In the axils of the upper 

 leaves are sometimes to be found numerous short clavate par- 

 aphyses, unicellular or of two or three oblong cells in a lineal series. 

 It is possible that the species deserves to be separated gener- 

 ically from Scapania, but in absence of perianth and sporogonium, 



■ 



we can do no better than refer it to a genus with which it surely 

 has very much in common. Our material is sufficiently ample to 

 allow its distribution at an early date in Underwood and Cook's 

 Hepaticae A mericanac. 



RlCCIA TRICHOCARPA. 



Thallus in rosettes about 2 cm. in diameter or forming some- 

 what irregularly radiating masses ; the principal divisions linear, 

 2-6 times dichotomous, .75-1.5 (mostly 1) mm. in width, often 



