BihUot/i-dphivdl Notices. VMy 



M. Ripart (Ann. d. Sc, Nat. S"" scr. vol. ix. p. 8(i), with regaitl to 

 Moi((f(oti((. Moiiijcotia (jenvjlexa is fignred at p. 112 in tlio 'Con- 

 spectus tionorum,' but in the description at p. 2r)H it is made a 

 synonym of Pleurocurpus mimhUis, Al. Br. If Plearocaqnis 

 mirabilis, Al. Br., and Afoio/eotia gemijlcxyt were really identical 

 (which, however, is probably not the case), there coiild l)e no possi- 

 ble ground for the substitution of the name I'leuroairpns for that 

 o{ M()ti(f(otia, the latter having been established bj' Agardh in 1824, 

 more than thirty years before the date of Braun's Pleamcarpvs. 



The remaining genera of the Zi/(/neme<i' call for no special remark, 

 except that it is veiy doubtful whether Mesucarjius is worthy of 

 being retained, or whether it ought not to be united with Moiujeotia. 



The Siphophijaxe constitute a small order, di\ided into two families, 

 \he Hydroffastne and the Vaucheriacece. Each family is composed of 

 only one genus. The former is represented by //y</yo;/rt.>.7y»//;,, Dcsv., 

 better known under the name Botnidhnn, -which name, however, is 

 of five ye^r;s' later date. The latter family is formed of the genus 

 Vaucher'ut, which of late years has been the subject of interesting 

 observations with regard to its method of impregnation. 



Dr. Rabenhorst's fourth order, the JVemfitophi/cecp, is divided by him 

 into aevon families:^!. Ulvacete; 2. SpJueropleacein; 3. Confer^ 

 vacecB; 4. (Ei/o^/otiiacece ; 5. Ulotrichece ; 6. Chroolepidieo' ; 7. Clwfo- 

 jihorerp. In the Ulvacece we have six genera, the first four of which, 

 viz. Protoderma, Prasiola, Phi/sodictifon, and Schizomerif;, are very 

 obscure, nothing whatever being known of their mode of propagation, 

 not even zoospores having been observed. The other two genera 

 are the well-known Entei-oniorpha and Ulvct. It would be bold to 

 question the validity of these long-established genera ; but, unless 

 Robin's assertions are correct (and, although made some years since, 

 they do not appear to be confirmed), no sexual reproduction is 

 known ; and the oceiuTcnce of zoospores is a matter of little moment 

 now that it is known that those bodies are not confined to Alga?, 

 but that they occur also in genera of Fungi, such as Ci/stojnts, 

 Peronospora, and Trichia, and, under favourable circumstances, 

 even in the gonidia of lichens. 



The second family of the Nematophijcece is the Sphfropleacece , 

 represented by the single genus SphceropJea, which possesses but 

 one species, Splu^ropJea anatdinu, a plant growing in Germany in 

 rtooded fields, and extremely interesting from the observations made 

 a few years since by Cohn with regard to its sexual reproduction*. 



The Confervacece (the third family), as limited by Dr. Rabenhoret, 

 consists of but nine genera, the best-known of which is Cladophom, 

 of which nine species are described ; but the well-known variability 

 of the plant is exemplified by the number of divisions, fornis, tfec. 

 into which the genus is cut up. In the present work the three 



Part III.) are called " Zygnemacoae " at p. 110. So, afterward.'^, "Ulo- 

 trichefe " (p. 280) are called •' I'lotrichaceic "' at p. 8(^0 ; and " Chicto- 

 phoref« " (p. 287) are called " Chietophoraceai ' at p. 374. 

 * See Ann. d. Sc. Nat. 4« s^r. vol. v. p. 187. 



