18 



CONFERVA CEiE. 



[Thallogexs. 



part of an inch. Their small end is the most transparent, and it is cui'ious to see how 

 constantly this is pushed forwards in the rapid evolutions made in the water by these 

 Uving particles. This sort of quasi animal life does not last long — a few seconds, some 

 minutes, or at the most half-an-hour. They often die : linger assures us that he has 

 seen them in the agonies of death, and struggling convulsively (!), with all the appear- 

 ance of animal Ufe. 



Porphyra laciniata and vulgaris are stewed, and brought to our tables as a 

 luxury, under the name of Laver ; and even the Ulva latissima, or green Layer, is not 

 sli'^hted in the absence of the Porphyrse. Ulva compressa, a common species on our 

 shores, is regarded, according to Gaudichaud, as an esculent by the Sandwich Islanders. 

 Common Nostoc, commonly called star-jelly, a trembhng gelatinous plant, that springs 

 up suddenly after rain, is by superstitious persons supposed to possess \4rtue as a 

 vuhierary, and in pams of the jomts ; oyster green or Ulva lactuca (the $pvou OaXdaaiov 

 of Dioscorides) is sometimes employed m scrofula ; the ancients used it in inflamma- 

 tions and gouty affections ; its taste is so bitter and salt that it is usually given with 

 lemon juice. 



The Confervals found in many thermal springs, mostly species of Sphaerozyga, are 

 used empirically as external applications to goitre, enlarged glands, &c. Henry has 

 examined the Confervals in the springs of Vichy, Neris, and Vaux, and foimd small 

 quantities of an alkaline iodide in each. (JJlieni. Gaz. 1844, p, 447.) 



GENERA. 



Suborder I. — Palmel- 

 lece. Cells somewhat 

 globose or elliptical, 

 free, and more or less 

 distinct, or collected 

 by means of a slimy 

 layer into a frond. 



Tribe 1. Protococcidae. 

 — The slimy substratum 

 obsolete. 

 Protococcus, Ag. 



Sphcerella, Somm. 



Coccophysium, Link. 



Gldbulina, Turp. 



Protosphceria, Turp. 

 Haematococcus, Ag. 



Gloiococcus, Shutt. 

 Chlorococcum, Grev. 



Glohiilina, Turp. 



Protosphceria, Turp 

 Pleurococcus, Mcnegh. 

 Hormospora, Breh. 

 Stereococcus, Kiltz, 



Tribe 2. Coccochloridae. 

 — The slimy substratum 

 evident. 

 Palmella, Lyngb. 



Priestleya, Meyen. 



Chaos, Bory. 



Phytoconis, Bory. 



Coccod^a, Pal. 



Merrettia, Gray. 



Sarcoderma, Ehr. 

 Coccochloris, Spr. 

 Microcystis, Kntz. 



Bichatia, Turp. 

 Anacystis, Memgh. 

 OncobjTsa, Ag. 



Hydrococci'is, Kiitz. 

 Micraloa, Biass. 



Ilydrothrombium, Ktz 

 Botrjdina, Brebiss. 



SuborderlT. — Nostochece. 

 Cells somewhat globose 

 or elliptical, coalescing 

 into a simple or bran 

 ched thread; united in- 

 to several rows bymeans 

 of a slimy substratum 

 of various forms. 



Nostoc, Vouch. 

 Linkia, Mich, 

 Undina, Fries. 

 Hydrococcus, Link. 



Thrombium, Wallr. 



Monormia, Berkel. 

 Sphserozyga, Ag. 



Anabaina, Bory. 



Trichormus, Allm. 

 Anhaltia, Schivabe. 



Suborder III. — Oscilla- 

 torea. Cells tubular, 

 naked or furnished with 

 a slimy or gelatinous 

 layer, continuous, but 

 seeming to be jointed 

 in consequence of in 

 terruptions of the co- 

 louring matter. 



Tribe 1. Rivularidse. — 

 Tubes proceeding singly, 

 or in pairs, from a trans- 

 parent globule ; collected, 

 into a frond by means of 

 a gelatinous layer. 



Gloiotrichia, J. Ag. 

 Rivularia, Roth. 



Lynchia, LjTigb. 



Gaillardotdla, Bory. 



Stylobasis, Schw. 



Stypnion, Raf. 

 Zonotrichia, J. Ag. 

 Diplotrichia, J. Ag. 



Tribe 2. Oscillatoridae. 

 — Tubes cyWidrical, free, 

 or u'oven into a frond 

 falsely jointed in conse- 

 quence of the ringed or 

 streaked appearance of 

 the colouring matter. 

 Oscillatoria, Bosc. 



Oscillaria, Bosc. 



Trichophora, Bonnem. 



Spirogyra, Nees. 



Spirulina, Turp. 



Loten, Adams. 

 Trichodesmium, Ehrenb. 

 Microcoleus, Desmaz. 



Vaginaria, Bory. 



Merizomyria, Poll. 

 Calothrix, Ag. 



Hempelia,^ Meyen. 



UlothHx, Kiitz. 



D-illwynella, Bory. 

 LjTigbya, Ag. 



Cyclosperma, Bonnem 



Humida, Gray. 

 Scytonema, Ag' 



Percursaria, Bonnem. 

 Sphseroplea, Ag. 

 Cadmus, Bory. 

 Sphcerogona, Link. 

 Sphceroplethia, Duby. 

 Beggiatoa, Trev. 

 Suborder IV. — Confer- 

 vece. — Cellules resem- 

 bling joints, arranged 

 in a net, or more fre- 

 quently in simple or 

 branched threads, se- 

 parate, or combined by 

 common slime. 

 Tribe 1. Hydrodicti- 

 dae. — Cells tubular, com- 

 bined by their pointed 

 extremities into a net-like 

 frond. 



Hydrodictyon, Roth. 

 Microdictyon, Dccaisne 



IHctylema, Raf. 

 Talerodictyon, Endl. 



Tribe 2. Zygnemidae.— 

 Cells tubular, united by 

 their truncated extremi 

 ties into jointed threads, 

 ivhichare at first distinct, 

 and then, by the aid of 

 transverse tubelets which 

 discharge the colouring 

 matter, brought into copu- 

 lation, 



Mougeotia, Ag. 

 Serpentitiaria, Gray. 

 Conjugata, Lk. 

 Zygnema, Ag, 

 Agardhia', Gray. 

 Globulina, Lk. 

 Stellulina, Lk. 

 Lucei-naria, Roussel. 

 Diadema, Pal. 

 Tendaridea, Bory. 

 Leda, Bory. 

 SpirogjTa, Lk. 

 Choaspis, Gray. 

 Salmacis, Bory. 

 Tribe 3. Confervidae. — 

 Cells tubular, united by 

 their truncated extremi 

 ties into free, simple, or 

 branched threads. 

 Myxonema, Fries. 

 Myxotrix, Fries. 

 Nenmtrix, Fries. 



Conferva, Fries. 



Polysperma, Vauch. 



Chloroniton, Gaill. 

 Hormiscia, Fries. 

 Xodularia, Mertens. 

 Aphanizomenon,Mor>'en. 

 Tiresias, Bory. 



(Edogonium, Lk. 

 Draparnaldia, Bory. 



Charospermum, Lk. 

 Leptomitus, Ag. 



Saprolegmia, Nees. 



Pythium, Nees. 



Sphcerotilus, Kg. 

 Achlj'a, Nees. 



Hydronema, Carua. 

 Hygrocrocis, Ag. 



Tribe 4. Chaetophori- 

 dae. — Cells tubular, ad- 

 hering by truncated extre- 

 mities in jointed branched 

 threads coalescing into 

 a gelatinous frond. 



Chsetophora, Schrank. 



Myriodactylon, Desv. 

 Hydrocoryne, Schwab. 

 Coleochaete, Breb. 



Suborder Y .—Siphonece. 

 Frond either monosi- 

 phonous, that is, con- 

 sisting of a single cell, 

 usually branched in 

 various ways, with the 

 branches continuous or 

 jointed, distinct or 

 variously united ; or 

 pleiosiphonous, con- 

 sisting of many tubular 

 cells , placed in contact, 

 branched, and various- 

 ly united or held to- 

 gether by means of 

 intercellular matter. — 

 Marine plants usually 

 covered with calcareous 

 incrustations. 

 Tribe l.Caulerpidae. — 

 Frond monosiphonous, 

 continuous, variously 

 branched, and filled with 

 the reticulated fibres of the 

 continuous brayich. 

 Caulerpa, Lamx. 



Chauvinia, Bory. 

 Tricladia, Dec. 



