Mr. Dawson Turner, who “after having observed its characters 
for many successive years” published an excellent account of it 
in the ‘ Linnean Transactions’ in 1801. It has always since been 
regarded as a distinct species, though confessedly very closely 
allied to D. Hypoglossum, and is now known to occur in the 
southern Hemisphere, as well as along several of the European 
shores. Specimens which I have gathered at the Cape of Good 
Hope appear identical with British ones. 
Mr. Turner, m the memoir alluded to, and in his subsequent 
works, has entered very fully into the points of difference between 
the present species and its nearest ally, D. Hypoglossum, figured 
in our first number. A comparison of the figures will make these 
differences obvious. In D. Hypoglossum the leaflets are lanceo- 
late, tapermg to each end, and generally, but not constantly, 
acute; in D. ruscifolia they are linear-oblong, much broader in 
proportion to their length, and always very blunt. But besides 
differences of form, which are not always constant, the cellules 
composing the membrane in the present species are much smaller, 
the substance denser and thicker, and the colour more intense 
than in D. Hypoglossum ; while the confervoid strize which traverse 
the leaves, and are readily seen in D. ruscifolia, are either very 
obscure or do not exist in D. Hypoglossum. 
Fig. 1. DeLnsspriA RUSCIFOLTIA ; with tetraspores. 2. The same, producing 
tubercles :—wnatural size. 3. a leaflet, with sori. 4. Portion of the same, 
showing the pellucid strie. 5. Tetraspores. 6. Leaflets with tubercles. 
7. Portion of the same. 8. Globule of spores, removed from tubercle. 9. 
Spores separated :—all more or less magnified. 
