The leaves of the British Columbia plants stand with their mar gins more often erect than in the California specimens, upon which our description and figures have been based. In the sterile con dition, Gyrothyra somewhat resembles the larger forms of AranThz collected by Macoun on Vancouver Island (Can. Hep. 8o).—but can readily be distinguished by the margined, lingulate, more translucent leaves and by the bifid underleaves.
The involucral leaves, though more or less apparently paired, are in a strict sense alternate like the cauline, and a single unpaired leaf is sometimes found to occur inside the pair we have de scribed as the uppermost.
It should be remarked that but few capsules of the plant have been seen and that these were already open or so young as to be still enclosed within the calyptra, so the actual dehiscence has not been observed, but the extremely long valves, which on being soaked out take easily a position strongly suggestive of the paring of an apple, the spiro-radial attachment to the basal disc, the never failing spiral twist of the valve-apex, and the spiral lines readily discernible on the surface of the embryo capsule (fig. up) make, in the judgment of the writer, the induction that the de hiscence is spiral so safe and certain that he has felt no hesitation in so describing it and in basing the generic name upon this char acter. The absence of thickenings in the walls of the cells of the capsule valves is noteworthy. Schiffner states of all the Jungermaniaceae akrogynae: "Die reife Kapsel besitzt eine aus 2 bis mehr Zellschichten bestehende Wand, deren Innen schicht in ihrcn Zellen stets Verdickungsleisten enthalt." In
Gyrothyra, the transverse walls of these cells usually appear a trifle thicker than the longitudinal, but the walls are otherwise wholly without traces of local thickening.
In respect to structure of the sporogonial envelopes, Gyrotkyra is one of several very interesting transitions from the ordinary Jun germania type to the various pouch-bearing genera. Considered from this point of view and from certain other gametophytic characters, its nearest affinities are undoubtedly to be found in that section of Nardia represented by Nardia /eaematosticta (Nees) Lindb., of Europe. In manner of dehiscence of capsule it recalls the marsupiiferous genus Kantza; but the valves of Gyrothyra are much longer and their cell-walls lack the local thickening, while, of course, no generic comparison of the two can be made so far as the gametophyte is concerned.
It is with pleasure that the author associates with this novel plant the name of one who, by his numerous papers upon the American Hepaticae, as well as by his unfailing generosity, has placed the younger workers in the same field under lasting obli gations. It should be noted that, although Professor Macoun's specimens were without the capsules, which reveal the distinctive generic character of Gyrotkyra, Professor Underwood had already recognized that they represented something undescribed.