454 Mr Kattray on the Distribution of 



Cramond Island, Inchmickery, or Inchcolm, and still less 

 so at or above North Queensferry, while the same is applic- 

 able to CoraUina officinalis^ Odonthalia dentata^ Delesse/ice, 

 FoIysijjJwnicc, Ceramice, and others. It is, however, remark- 

 able that it is not always the species that is highest in the 

 more seaward places that extends furthest in a landward 

 direction. This occurs in the cases of Fucus canaliculatus, 

 as compared with F. 2:)latycarpu8 and F. serratus; and it 

 may also be noted in the case o^ Laminaria doustoni and L. 

 sacdiarina, as contrasted with Alaria esculenta, and Sacco- 

 rhiza hulbosa, or of OdonfJialia dentata as against Foly- 

 siphonia urceolata, and of CoMitliamnion turneri as against 

 C. plumula, &c., the latter having been found at a depth of 

 about twenty-five fathoms, growing on a Pecten shell, to 

 the south of the May Island, and having also been dredged 

 to the east of Inchmickery in a depth of from 3 to 4 

 fathoms. The delicate Floridece become more and more 

 abundant for a given depth as one passes from Queensferry 

 to the May Island. The Folysiplwnice, Delcsserice, Ceramia, 

 Callithamnia, Griffithsice, Fhyllojpliorce, Plocamia, &c., may 

 all be noted in this connection. 



(2) As to the size of specimens from different localities, 

 but at corresponding depths within the limits of the tidal 

 belt, many measurements have been recorded from time to 

 time, but it may be said generally that the best data have 

 been procured from specimens collected on the shores of the 

 various islands, since here no disturbing influences are at 

 work, either to artificially accelerate or retard growths, as 

 not uncommonly happens on the shores of the mainland. 

 In the following table the averages of the sizes taken from 

 many specimens are given, as well as the places of growth, 

 and the position with respect to depth : — 



[Table. 



