450 MR. E. A. L. BATTERS ON 
aerial roots. It occurs to me that this may be connected with 
the fact that the mode of origin of the former is exogenous, that 
of the latter endogenous. Rhizophores, however, in this respect 
resemble branches. While it appears to me as incontestable that 
the scars of Ulodendron were due to the disarticulation of axial 
organs of some kind, there is nothing, I think, improbable in 
the suggestion that they may have belonged to rhizophores ; and 
the view is, at any rate, one which is worth consideration. W. T. 
THISELTON DYER. | 
DESCRIPTION OF PLATE XVII. 
Anatomy of Leaf-scars. 
Figs. 1, 2. Section of Dammara robusta, at the junction of branch and stem. 
Figs. 5, 6. The same. 
Fig.7. Exterior view of scar of Dammara, from which a branch has fallen. 
Fig. 3. Leaf-articulation of Horse-Chestnut (JEsculus Hippocastanum) showing 
course of fibro-vascular bundle. 
Fig. 4. Old leaf-scar in same, showing rupture of the fibro-vascular bundle by 
the cambial growth of the wood. ` 
A Description of three yew Marine Algæ. 
By Epwarp A. L. Barregs, B.A., LL.B., F.L.S. 
[Read 15th March, 1888.] 
(Prate XVIII.) 
Ectocarrus Hotmesir. (Plate XVIII. figs. 7-16.) 
E. cwspitosus, thallo 3-1 cm. alto, filis parce ramosis, implexis, 
ramulis brevissimis secundis curvulis, sub angulo recto vel fere 
rectoegredientibus, articulis 14-2 diametro lon gioribus, sporangiis 
subsessilibus vel plus minusve pedicellatis, latere ramorum 
secundis, unilocularibus, sphzricis vel ovatis, circiter 62 p longis, 
4S p crassis, multilocularibus, ovato-conicis, 230 p longis, 44 p 
crassis. 
Hab. Torquay, Minehead, Berwick-on-T weed. 
A small species seldom more than a quarter of an inch in 
height. It covers the rocks for a considerable distance with & 
soft brown turf, the patches often being four or five feet 1D 
diameter. The filaments are so short that it is almost impossible 
to detach them from the rock without the aid of a knife or 
similar instrument. At Minehead it grows on woodwork ; but 
Mr. Holmes tells me he found it growing on ledges of rock, m 
