310 Proceedings of the Boijal Irish Academy. 



(b) The f ollowiug should be grouped as doubtful species : — Anabaena 

 polysperma Kiitz., Oscillatoria percursa ^t/fe., 0. subtilissima ^«te, 0. violacea 

 Hnss., Phormidium Boryanum Kiitz., P. leptodermum Kittz., Ei\ularia gianuli- 

 fera Cana., Sphaerozj'ga fiexuosa Ag., S. Mooreaua i?«{/k, Symploca Flotowiaua 

 Kiitz. 



(c) Microcystis aeruginosa G. S. West should be M. aeruginosa Kiitz., 

 Scytonema mirabile Born, should be S. mirabile Thur. 



Desmidiaceae. 



(a) The following species should be deleted : — Artlirodcsmus longicornis 

 Hoy, A. Ealfsii West, Closterium obtusum £rib., U. subtile Breb. (occurs 

 twice, and both should be deleted), C. toxon West (occura twice, and one of 

 the records should be deleted), Cosmarum angustatuni Nord., C. ansatum 

 Kiitz., C. bipapillatum West, C. confusum Cooke, C. crenatum Balfs., C. curtum 

 Brib., C. cylindricum Bal/s., C. Elfvingii Bacib., C. geuimiferum Br^b., 

 C. Klebsii Ghitw., C. Malinveruianum Schnidle, C. Nuttallii West, C. platy- 

 isthmum Arch., C. Scenedesmus BcIjk, C. sinuosum Lund., C. sublobatum 

 Arch., C. subpuiictulatum i\'t>/-(/.s/., C. Subreinscliii Schmidk, C. succisuui West, 

 Cylindrocystis quadratum Nordst., Docidium dilatatuni Lund., D. nobile 

 Lund., Enastrum circulare Haas., E. pyraniidatum West, E. scitum West, 

 Gonatozygou Ealfsii De Bary, Mesotaenium Braunii De Bary, M. micrococcum 

 Kirchn., Mierasterias brachyptera Z«/k/., JI. fimbriata IMfs., M. furcata Ag., 

 51. luucroiiata Rabh., M. radiosa Ag., Ouycliouenia filiforme Hoy ct Biss., 

 Oocardium stratum Nag., Penium lamellosum Brib., P. rufopellitum Boy, 

 Pleurotaenium clavatum Dc Bary, P. minutum Delpontc, P. nodulosum Be 

 Bary, P. rectum Dclp., Sphaerozosma secedens Dc Bary, Spirotaenia endospira 

 Arch., Staurastrum eustephanum lia/j's., S. pseudofurcigerum Reinsch., S. 

 trachynotum West, S. tricome Memgh., Xanthidium bisenarium Ehr. 



{b) The following should be grouped as doubtful species:— Cosmarium 

 giavatum Arch., C. lasiosporum Arcli., C. lobatospoiaim Arch., C. Wrightianum 

 Arch., Docidium hirsutum Bail. 



(c) Cosmarium humile Gay should be C. humile Nordst., C. istmochondrum 

 Nordst. dhould be C. isthmochondrum Nordst., Xanthidium armatum Babenh. 

 should be X. armatum Brib. 



Othek Conjugatae. 

 The following species should be deleted ; — Mougeotia laevis Arch., Zygnema 

 didymum Babh. 



Freshwatek Chlokophtceae. 

 (a) The following species should l>e deleted : — Crucigeuia pulchra W. & 

 G. S. West, Gloeoc»x:cus luucosus Br., Gloeocystis amplu B'lhli.. (\. Iniiuicola 



