452 Mr Eattray on the Distrihution of 



lain for some time in the wash of the tide tliey often 

 become co^^ered with a growth of Uloilirix fiacca, com- 

 mingled with Urospora ]jenicilliformis, the latter forming 

 elegant dark-green streaks, of a somewhat glossy appear- 

 ance, among the fronds of the former. Catenella opuntia is 

 pre-eminently a high-water species; nor does it appear to be 

 greatly influenced by the muddy or clear character of tlie 

 waters, having been observed from Caroline Park to the 

 eastward. Callitliamnion rothii is very common, e.g., Caro- 

 line Park and Inchcolm eastwards in this belt, especially 

 in its lower reaches ; C. floridulum^ though present, belongs 

 rather to the Fucus zone. 



If a comparison be made at different places (e.gr., Inch- 

 colm, Inchkeith, Fidra, the Bass Kock or May Island, 

 and the corresponding north and south coasts) of the 

 products of the various zones, i.e., if the superficial extent 

 be considered, the following general statements may be 

 arrived at : — 



I. Some species may be regarded as having a very 

 wide or general range, among which may be noted the 

 following : — 



A . Eiitermorpha area : — 



Enteromoi^plia intestinalis, E. compressa, Prasiola mariTia, 

 Monostroma latissimum, Porpliyra laciniata, P. vulgaris, 

 Ulothrix fiacca, Urospora penicilliformis.^ CladopJiora Iceti- 

 virens, &c. 



B. Fucus area : — Fucus nodosus, F. platycarpus., F. 

 vesiculosus, F. serratus, Halidrys siliquosa, Litliotliarnnion 

 polymorplmm., Elachistea fucicola, Callithamnion rothii, 

 Ectocarpus littoralis, E. siliculosus, Dumontia filiformis.^ 

 Gigartina mamniillosa, Polysipjhonia nigrescens, P. fasti- 

 giata, Ghondrus crispus (as well as deeper), &c. 



C. Gorcdlina area : — Gorallina officinalis, Odonthalia 

 dentata (and deeper) Phodomela suhfiisca, Rhodymenia 

 palmata (or deeper), Rcdfsia verrucosa. Poly ides rotundits^ 

 Leathesia tuheriformis, Petrocelis cruenta, Ceramium acoM- 

 thonotum, &c. 



D. Sphaccllaria-Griffithsia area : — Furcellaria fastigiata, 

 GhordcB, Laminaria cloustoni, L. saccharina, Gystoclonium 

 purpurascens, Gallithamnia of various species, Phyllophora 



