BOTANY CERAMIACEiS {continued) — Ceramium diaphanum, Roth. — gracillimum, Griff, and Harv. — nodosum, Kutz. Griffithsia equisetifolia, Ag. — simplicifilum, Ag. — setacea, Ag. Callithamnion plumula, Lyngb. — turneri, Ag. — pluma, Ag. — tetricum, Ag. — hookeri, Ag. — roseum, Lyngb. — byssoideum, Arn. — polyspermum, Ag. — fasciculatum, Harv. — borreri, Ag. — thuyoideum, Ag. — pedicellatum, Ag. — rothii, Lyngb. — daviesii, Lyngb. CHLOROSPERMEiE SlPHONACEi* Bryopsis plumosa, Ag. — hypnoides, Lamour. Cladophora pellucida, KUtz. — diffusa, Harv. — rupestris. Kg. — laetevirens, Kutz. — flexuosa, GriflF. SiPHONACEit [continued) — Cladophora gracilis, GrifF. — refracta, Kutz. — albida, Kutz. — lanosa, Kutz. arcta, Kutz. — flavescens. Kg. — fracta, Kg. Rhizoclonium riparium, KUtz. Conferva linum. Roth. — tortuosa, Dillw. — melagonium, Web. and Mohr. — aerea, Dillw. — coUabens, Ag. — youngana, Dillw. Enteromorpha cornucopiae, Hook. — intestinalis, Link. — compressa. Grev. clathrata, Grev. — percursa. Hook. Ulva latissima, Linn. — lactuca, Linn. — linza, Linn. Porphyra laciniata, Ag. — vulgaris, Ag. Bangia fiisco-purpurea, Lyngb. OsCILLATORIACEiE Rivularia atra, Roth. Calothrix confervicola, Ag. — scopulorum, Ag. Lyngbya flacca, Harv, DIATOMACEiE This extensive and interesting Order has received much attention in Norfolk having been studied for many years by Thomas Brightwell, R. Wigham, J. Bleakley, H. G. Glasspoole and W. K. Bridgeman and others, and especially by Frederic Kitton, Hon. F.R.M.S., a specialist of more than European fame. Mr. Kitton published papers on the distri- bution of this Order in the county in the Transactions of the Norfolk and Norwich Naturalists' Society, and he drev^ up a complete list for Mason's History of Norfolk in which he enumerated 65 genera and 310 species with full account of the localities in which they had been found, which may be summarized as follows : ' The system of classification adopted is, with a few slight excep- tions, that of Prof H. L. Smith, of New York.' Amphora, Ehrenberg Cocconema „ Cymbella, Agardh . Encyonema, KUtzing Mastogloia, Thwaites Navicula, Ehrenberg Scoliopleura, Grunow Brebissonia ,, Stauroneis, Ehrenberg 6 species Amphipleura, KUtzing . 4 „ Schizonema, Agardh 2 „ CoUetonema, Brebisson . 2 „ Berkeleya, Greville . . 3 „ Stictodesmis „ . • 72 „ Amphiprora, Ehrenberg 3 „ Pleurosigma, Smith . . I „ Toxonidea, Donkin . 8 „ Rhoikosphenia, Grunow 69 I 3 3 I I 6 14 2 I species