FLORA OF ALDERXEY. 271 



DESMIDIACEjE. 



*Cosmarium pyramidatum, Breb. In profusion among tufts of (Edogonium 



on dripping rocks under Fort Albert. 

 *C. bioeulatum, Breb. In a water-trough on the cliffs below the old mill, 



scarce. 

 *"C. undulatum, Cord. Pool in Mauney quarry, scarce. 

 C. tetraophthalmum, Kiltz. With the last species, also scarce. 

 C. BotrytiS, Bon/. In great profusion in a cliff quarry pool towards Le 

 Becquet, and in the Mauney quarry pool. Moderately plentiful in the 

 marsh at Clanque, and in the old quarry below Fort Essex. Less com- 

 mon at Longy Pond, Val du Sud, Corbel ets, and several other localities. 

 Closterium Lunula, Mall. Cliff marsh at Clanque, scarce. 

 C. aeerOSUm, Schrank. A pure gathering (some in conjugation) in a small 

 pool at Clanque. Frequent in the pool in Mauney quarry. Marsh at 

 Val du Sud, a very large form. A small form at Trois Vaux. Also 

 found in several other places. This species and Gosmarium Botrytis are 

 by far the commonest Desmids in Alderney. 

 *C. Leibleinii, Kiltz. Old quarry pool at Clanque Bay, scarce. 

 C. Dianse, Ehr. Abundant in the pool in Mauney quarry. 



