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<!Drigmai 3lls:tkic.0. 



ON ANOMOCLADA, A NEW GENUS OF HEPATICJ^, AND 

 ON ITS ALLIED GENEEA, ODONTOSCHISMA AND 

 ABELANTHUS. 



By Richard Spruce, Ph.D., F.R.G.S., &c. 



(Tab. 176, 177.) 



{Continued from p . 136.) 



In Pteropsiella. feondiformis, nov. gen. — a curious Hepatic 

 gathered by myself on the Kio Negro, with broad linear fronds recalling 

 small plants of the Fern Pteropsis furcata. yet with postical inflorescence, 

 of both sexes, scarcely distinguishable from that of Cephalozia, from 

 which the habit is, in other respects, totally diverse — the male flowers, 

 although usually occupying the whole of a long slender postical 

 spike, are also often fonnd continuous with the apex of the main 

 frond, or occupying the base or the apex of a frondose branch. 

 In this case the transition from a linear frond, traversed by a 

 medial costa, to distichous bifid leaves, is very instructive ; for the 

 change is very rapidly efi'ected, and is much the same as if the leaves 

 should be cut out of a sheet (the pagina of the frond) with scissors, and 

 set on again to the costa or stem — not longitudinally, as when united 

 into a continuous flat membrane, but obliquely — at first slightly so, 

 but gradually more inclined, until they become nearly transverse. 

 This gives them standing room, for they are only half as long as the 

 breadth of the pagina, but twice as broad as the space they would have 

 occupied if placed lengthwise of the stem ; being made up of almost 

 exactly the same number of cells as a corresponding portion of the un- 

 divided pagina. The leaves, or more properly bracts, thus "cutout" 

 are ovato-quadrate, concave, emarginato-bifid, the apices being apiculate 

 with a single long truncato-conical cell. The upper bracts (in a terminal 

 spike) are the most modified and the most exactly transverse, and they 

 each enclose a solitary antheridium, placed near the antical angle of 

 their base ; the lower bracts being usually empty. 



The antheridia of Hepaticse, whether solitary, as in a great many 

 genera, or grouped by twos, threes, &c., as in others, always stand 

 along each margin of the upper side of a stem or branch — or of the 

 costa in a frondose species — «.e., they are semi-antical ; and there is 

 no exception to this in the entire family. Where there already exists 

 a leaf or lobe in that position {i.e., incubous) it has only to be 

 slightly modified to shield the antheridia ; but where the leaves are 

 purely succubous, a semi-antical lobe is generally added on for that 

 purpose, or the leaf is simply dilated in front. In a very few genera 

 the antheridia remain unprotected, no addition being made to the 

 upper margin of the adjacent leaves, as in Fossomlronia ; in others 

 they are buried in alveoles of the costa, and at first shielded by the 

 N.s. VOL. 5. [June, 1876.] M 



