94 < DUBLIN UNIVERSITY 



FRIDAY EVENING, APRIL 16, 1858. 



Eobert Harbison, M. D., Professor of Anatomy and Lecturer in 

 Zoology, in the Chair. 



The Minutes of last Meeting having been read, were approved of, and 

 signed by the Chairman. 



The following paper was read by "William Archer, M. E. D. S. : — 



SUPPLEMENTARY CATALOGUE OF DESMIDIACE-E FOUND IN THE NEIGHBOURHOOD 

 OF DUBLIN; WITH DESCRIPTION AND FIGURES OF A PROPOSED NEW GENUS 

 AND OF FOUR NEW SPECIES. 



(WITH PLATE XI.) 



On a former occasion I had the pleasure to read to this Association a 

 Catalogue of Desmidiacese found by me in the neighbourhood of this 

 city, which the Council did me the honour to print in the Proceedings. 

 It is now my privilege to be permitted to follow up that list with a sup- 

 plementary one, containing such additional species as resulted from some 

 gatherings made during the last summer, and, in addition to the species 

 hereafter to be enumerated, which are contained in Ralfs* "British 

 Desmidiae," to bring to notice and to describe four new species ; and, 

 although two of them are very minute, and the others not so striking as 

 many of the other members of this interesting group, I do so with the 

 hope that these additions to our Flora may be to some not without their 

 interest. 



For the reception of two of the new forms to which I think I am 

 the first to direct attention, I now venture to form a new genus ; and, 

 while opposed (as I should undoubtedly be) to the formation of unne- 

 cessary generic characters and names, I do not think that in proposing 

 a new genus, I have, in the present instance, fallen into so grave an 

 error. I admit I am myself inclined to think it true that genera, like 

 species, have an existence in nature, — an opinion held, I imagine, by 

 the minority ; however, there can be no doubt that many of the genera 

 of our systems cannot be strictly natural, and this perhaps sometimes 

 arising from a desire to divide into two or three other genera, possibly 

 a good and natural genus, merely because, containing numerous species, 

 it is thought too cumbrous and unmanageable, or from the natural and 

 true characters limiting each genus not having been arrived at. In 



