A HISTORY OF SUSSEX Rhodomeniace^ Rhodymenia Palmetta, Grev. Hastings Sphasrococcus coronifolius, Ag. „ Gracilaria erecta, Grev. Hastings Cryptonemiace^ Gigartina acicularis, Lam. Hastings Chondrus Norvegicus, Lam. Brighton Gymnogongrus Griffithsia, Mart. „ Phyllophora palmettoides, J. Ag. Hastings Halymenia ligulata, Ag. Hastings Ginannia furcellata, Mart. „ Crouania attenuata, J. Ag. „ Naccaria Wiggii, Fries. Brighton Gloiosiphonia capillaris, Carm. Brighton Nemaleon purpureum, Harv. „ Dudresnaia coccinea, Bonnem. „ Ceramiace^ Ceramium botryocarpum, Grev. Hastings — Deslongchampsii, Cham. Eastbourne — diaphanum, Ag. Brighton — gracillimum, Grev. Hastings — echionotum, Ag. „ Griffithsia equisetifolia, Ag. Seaford ■ — barbata, Ag. Brighton — Devoniensis, Harv. Brighton Wrangelia multifida, J. Ag. Hastings Seirospora Griffithsiana, Harv. Brighton Callithamnion plumula, Lyng. „ — cruciatum, Ag. Brighton — roseum, Lyng. „ CERAMIACEi^ {continued) — Callithamnion byssoideum, Arnott. Brighto, — Turneri, Ag. „ — polyspermum, Ag, „ — Borreri, Ag. „ — floridulum, Ag. „ — Hookeri, Ag. Eastbourne — thyoideum, Ag. Hastings CHLOROSPERMEiE SiPHONACEiE Codium bursa, Ag. Brighton Bryopsis plumosa, Lam. Eastbourne CoNFERVACEi?: Cladophora rupestris, Kutz. Eastbourne — gracilis, Griffiths. Hastings — Rudolphiana, Kutz. „ — albida, Kutz. Shoreham — lanosa „ Brighton — glaucescens, Harv. Brighton Conferva arenicola, Berk. Hastings — melagonium, Web. Shoreham — aerea, Dill. Brighton Ulvace^^ Enteromorphe erecta, Hooker. Hastings Ulva linza, L. Brighton Bangia fusco-purpurea, Lyng. Brighton OsCILLATORIACEiE Calothrix confervicola, Ag. Brighton Oscillatoria subsalsa, Ag. „ THE LICHENS {Lichenes) Among the Cryptogams the lichens are perennial plants composed of cells so arranged as to form a foliaceous, woody, scaly, crustaceous or leprous thallus, or fusion of root, stem and leaves into a general mass. They like bright sunshine and fresh air, and die in an impure atmosphere. They occur under very varied conditions, on rocks, on the chalk downs, in bogs, on the bark of old trees, on old barn doors, and on the flints and boulders along the coast. Although studied but by a few of our botanists, Sussex has not been neglected in this respect, and although not possessing a knowledge of them myself, I have accompanied rambles in search of them with pleasure. Borrer, who published little under his own name, in conjunction with his friend Dawson Turner, wrote An Attempt at a History of the British Lichens. This had a private circulation only, but in its dedication a belief was expressed that it would be a monument of his industry, ability and profound knowledge of our lichens. In east Sussex we have lists made by Roper and Bloomfield, from which I quote, and from west Sussex one by Mr. W. C. Cooke, brother of Dr. Cooke, the well-known cryptogamist. This catalogue made by him for the Chichester Society I have now before me, and from this I give many of the habitats of our Sussex lichens. The following list is arranged according to Leighton's Lichen Flora of Great Britain. 64