136 Algae. - Fungi, Myxomyceten, Pathologie. 



lime and the presence of humic arid in the water, these conditions 

 being rendered possible by the geological nature of the areas in 

 question, which are suitable for the formation of peatbogs and peaty 

 pools. The diversity of the Desmid-flora and the presence of some 

 of the handsomest species of the family appear to be directlj' con- 

 nected with the antiquity of the geological formations. 



5. The Desmid-flora differs essentially from that of the small 

 peaty pools and bogs of the same area, especially in the relative 

 abundance of the species common to both the bogs and the plankton. 



6. The Desmids were doubtless originally derived from the 

 pools and bogs of the mountains, and only those species have 

 flourished which found the conditions most suitable for their existence 

 as pelagic organisms, some of them having in course of time pro- 

 duced distinct and characteristic plankton-varieties. 



7. There is no very obvious maximum development of Diatoms, 

 and some of the larger species of the Naviculoideae and Surirelloideae 

 have firmly established themselves. 



8. The Proportion oi Myxophyceae is relatively small, and species 

 of Oscillatoria , Lynghya, and other genera are somewhat scarce. 



E. S. Gepp. 



Arthur, J. C, Uredinales: Coleosporiaceae , Uredinaceae, Aecidi- 

 aceae (pars). (North American Flora. VII. p. 83—160. 1907.) 



In this paper the author treats the above mentioned groups of 

 the Uredinales. The family Coleosporiaceae is div^ided into two 

 genera; Coleosporiuin and Gallowaya. The Uredinaceae are divided 

 into eighteen genera as follows: Uredo , Physopella , Bubakia, Piicci- 

 niastriirn , Melarnpsoridiiim , MelarnpsoreUa , Hyalopsora, Calyptospora , 

 Necium nov. gen., Uredinopsis, Melanipsoropsis, Cronartiian, Cero- 

 teliiim, CionotJirix nov. gen., Alveolaria, Baeodroniiis , Endophylliun 

 and Pucciniosira. The family Aecidiaceae are divided into thirty 

 seven genera as follows: Neoravenelia, Cystingopiiora nov. gen., 

 Ravenelia , Dendroecia, Dicheiriyiia gen. nov., Pileolaria , Discospora 

 gen. nov., Hemileia, Transschelia, Polythelis, Phragnwpyxis, Uro- 

 pyxis, Calliospova and Prospodiiini. The remainder are to be given 

 in the next number of the Flora. 



The new species are: Coleosporiinn Begoniae Arth. on Begojiia 

 sp, from Mexico, C. Laciniariae Arth. on Laciniaria sp. from Florida 

 and Alabama, C. arnicole Arth. on Arnica cana from Washington, 

 C. occidentale on Senecio JiydropJiiloides from Washington, Biibakia 

 rnexicaiia Arth. on Croton spp. from Mexico, Neciiun Farlowii Arth. 

 on Tstiga canadeiisis (L.) Carr. in New England, Uredinopsis PJie- 

 gopteridis Arth. on Phegopteris Dryopteris (L.) Fee from Wisconsin, 

 Melanipsoropsis Piperiana Arth. on Rhododendron caUfornicuni Hook. 

 in Oregon and Washington, Ravenelia igualica Arth. on Acacia 

 filicidoides (Cav.) Trel. in southern Mexico, R. mimosicola Arth. on 

 Miinosa spp. in southern Mexico, R. irvegidaris Arth. on Cracca 

 macrantha (T. & G.) Rose in Mexico, R. caidicola Arth. on Cracca 

 cinerea Morong in Bahamas, Pileolaria extensa Arth. on Pistacia 

 rnexicana H. B. K. in Mexico, P. niexicana Arth. on Syphonia mollis 

 (H. B. K.) Nutt. in Mexico, and Uropyxis Roseana Arth. on Cracca 

 Talpa (Wats.) Rose in Mexico. 



The following changes of names have been made: Uredo ribicola 

 C. & E. to Coleosporium ribicola (C. & E.) Arth., Stichopsora Ment- 

 seliae Diet. & Holw. to Coleosporium Mentseliae (Diet. & Holw.) Arth., 



