ON THE UESMlDIEiE OF NORTH WALES. 18 



ON THE DESMIDIE^ OF NORTH WALES. 



Read before the Society, May lotii, i(S8i, 



Duriiijj the uiiusnally hot month of Auf^ust of hist year, I spent 

 several weeks at Capel Curi<,', makiiif^ that phice my centre, and 

 taking daily rambles in the iiei<»hbourhood extendinjj to Beddgelert, 

 Ffestiniof», the Ogweu Valley, and to every peak and ridge in the 

 ranges of Snowdon, the Carnedds and the Glyders ; and, of course, 

 to the intervening valleys, with their streams and bogs, and to 

 the wild moorlands in which the disti'ict abounds. These latter 

 are the especial haunts of those beautiful plants, the Desmidieae, 

 but the long drought which prevailed at that time had dried up most 

 of the pools and boggy places in which they are to be chiefly sought, 

 and, on the whole, my gatherings were disappointingly few in number 

 and unproductive in kind, although here and there some rare species 

 was found. During these rambles, I had many times passed and 

 re-passed the little foot bridge which spans the river issuing from 

 Capel Curig lakes and leads across into the wooded slopes of 

 Moel Siabod, and had often lingered to watch the sportive movements 

 of the shoals of small fish which were constantly gambolling in the 

 sun. On the last day of my stay, I was enjoying the dolcc far nieiite at 

 this spot, and regi-etting mentally that next morning would see me with 

 my neck in the accustomed collar, when my eye rested on certain small 

 bright green spheres among the weeds below, and I immediately 

 fetched a bottle and bore some of them off to my lodgings for cui'sory 

 examination. They proved to be masses of the well-known Infusorian, 

 Ophnjdium versatile, but attached to or embedded in these were 

 several Desmidiese new to me, and on examining fragments of the 

 weeds which accompanied the Ophrydium, I found that these were 

 the nidus of still larger numbers of the Desmids. I had only time to 

 run down to the lake with two or three bottles, and to cram these 

 with myriophyll and other water weeds, and to take iny departure 

 from these happy hunting grounds by the inevitable coach. 



On my arrival at home, this material was well washed out in a 

 basin of water, and the resulting sediment transferred to several large 

 bottles, and for some days frequent changes of water made, so as to 

 get rid of the bulk of the slimy unstable vegetable matter which 

 abounded. There remained a flucculent brown deposit at the bottom 

 of each vessel, very rich in Desmidieae, and affording ample scope for 

 many evenings' work. This material proved extremely rich in those 

 elegant, but very puzzhng plants, the Staurastra. A considerable 

 number of species, both of this and of other genera, are hitherto 

 unrecorded in England ; others have not been detected in any part of 

 Great Britain, while several appear to be hitherto unknown. 



I have here gratefully to acknowledge the great kindness of Dr. 

 M. C. Cooke, to whom I have submitted either specimens or 

 drawings of the whole of these new or rare species, and who has not 



