PROCEEDINGS OF SOCIETIES. 



Dublin Micboscopical Club, 

 IGth April, 18G8. 



Dr. John Barker sliowed specimens of Micrasterias Jlnibriata, 

 Halfs, taken near Carrig Mountain, new to Ireland, possessing, 

 besides the ordinary characteristics of this fine species, the 

 additional one furnished by the presence of a number of acute, 

 soQiewhat curved spines, variously, but seemingly definitely, dis- 

 posed over the surface. A series of these spines ran in a curve 

 near the base of each segment across its whole width, and a series 

 of similar spines ran close to and parallel with the margin at 

 each side of the end lobe, whilst a few others were disposed here 

 and there (seemingly definitely, though not in rows) over the sur- 

 face. Inasmuch as no spines, beyond those at the tips of the 

 teeth, thus fringing the margin of the frond, have been mentioned 

 by any writer who records tliis species (except by Bulnheim, in 

 * Hedwigia,' ii, p. 21, providing that the form there mentioned be 

 the same as the present). Dr. Barker was inclined to suppose this 

 form may, probably, eventually be regarded as a distinct species, 

 owing to the presence of these spines, notwithstanding the outline 

 and general character of the forms agreed so closely with the 

 published figures. It would, however, be the safer course simply 

 to record this interesting form, leaving it for the future to com- 

 pare it with foreign specimens, or until both be found con- 

 jugated. 



Mr. Archer expressed his strong opinion at present that the 

 very pretty form exhibited by Dr. Barker could not be regarded 

 as distinct from Micrasterias finibriata, Ralfs, notwithstanding 

 the presence of the superficial spines, inasmuch as the general 

 form of the cell, and disposition, character, and number of the 

 lobes, agreed so completely with Kalfs' figure, as well as that of 

 Pocke in his ' Physiologische Studien,' t. i, fig. IG (whicli he 

 showed), which was doubtless the same plant, though there 

 called JEuastrum \_Micrasterias'] apiculatum ; but M. apiculata 

 (Ehr.), Halfs, seems to be another plant. No doubt the spines in 

 lines on the surface were a remarkable addition to the characters 



