ON ANOMOCLAD.V. 133 



Fern-pinna., from the cataracts of the Rio Negro, on which arc growing, 

 side by side, a tine Moss, Hookaria Pafrisue. Hpe., notable for the 

 metallic green of its flattened tetrastichous leaves, and a Hepatic, 

 Lejeunea lunulata, Web., of about the same size as the Moss, hut of a 

 rufous hue. The rootlets of both spring from the underside of the 

 stem, and in both spread out into small, compact disks (haustoria) that 

 closely adhere to the Fern, without penetrating it ; yet in the Moss I 

 am required to say they arise from tlie back, and in the Hepatic from 

 the bellt/, of the stem ; and such instances might be multiplied indefi- 

 nitely. Surely it is better to revert to the usage of such eminent 

 botanists as Hooker, Weber, Martins, &c., and call the underside of 

 the stem of a Hepatic the hack, as we do that of a Moss. Most writers 

 call the underside of a leaf the back, even those who affirm the con- 

 trary of the stem, and where the two modes come into collision (as 

 they do sometimes in the descriptions of even the accomplished 

 authors of " Synopsis Hepaticarum' ) the result is rather perplexing. 

 Besides, we are not ashamed to say, in Latin, " rami caulis ventre 

 enati," but our English reticence obliges Dr. Carrington to use such 

 circumlocutions as "branches springing from the ventral aspect of the 

 stem." To avoid all misconception on this head, I do not use at all 

 the terms dorsal undL ventral, but in their stead antical and postical, in 

 their ordinary and well-understood sense. The postical leaves I have 

 long called, in my MSS.,/o//o^rt, little leaves, for they are only in very 

 rare cases as large as ttie lateral leaves, and are very often many times 

 smaller ; in conformity with this the postical bracts become naturally 

 bracteolcB. They might be called rhkophyllaov rhizimphylla, because they 

 bear the rhizina; but it would be a needless multiplication of terms. 

 The term stipule may still be used for these appendages, by those who 

 prefer it, without any risk of being misunderstood ; they are, how- 

 ever, by no means analogous to the stipules of flowering-plants, for 

 intead of being normally two to each leaf they are usually only half 

 as numerous as the leaves, and they never subtend the leaves as true 

 stipules do. 



A careful study of the stipules, or amphigastria, of Hepaticse 

 can lead to but one conclusion, namely, that they are truly and simply 

 leaves, differing in no essential respect from the lateral leaves, and 

 having their analogues in the allied family of Mosses, where it has 

 not been found necessary to give them any special name at all. In 

 almost any Moss with complanate foliage, e.g., in Eypopterygium, 

 Distichophyllum, in many species of Hookeria, &c., the postical leaves 

 (where they exist at all) will be found smaller, more symmetrical, and 

 more nearly transverse in insertion than the lateral leaves, which are 

 always more or less oblique and unequal-sided. But these are pre- 

 cisely the most usual points ot difference between the amphigastria and 

 the lateral leaves of a Jungermannia. 



Having settled these essential preliminaries, I proceed to off'er a 

 detailed description of Anomoclada. 



Anomoclada, Spruce, gen. nov. 



Flantcc lignicolee, mucosfc, dense depresso-csespitosae, serpentino-rep- 

 tantes, vamo? foliosos floresque femineos e caulis facie antica 



