llEC. 1893.] HOTANICAL SOCIETY OF EDINBURGH. 79 



A Xew Species of riiACELOCARPUS. By E. M. 

 Holmes, F.L.S. 



(With Plate I.) 



(Read March 1892.) 



Ill the Epicrisis Systematis Floridcarum, Dr. Agardh 

 describes six species of the genus, and another has since 

 been added by him in Till Algcrnes Systematik, iv. p. 57. 

 These algae are confined to the coasts of Australia, New 

 Zealand, and South Africa. The genus has been divided 

 into two sections, the first, Eudcnodus, having compressed, 

 pinnately decompound, linear branches and branchlets, 

 which are distichously pinnate throughout, and the second, 

 Fhacclocarpus, a more or less cylindrical or terete irregularly 

 branched frond, with the ultimate pinnules or teeth 

 arranged in an irregularly spiral manner around the 

 stem. 



The first section includes P. alatus, P. complanatus, 

 P. sessilis, P. apodus, and P. Lahillardicrii, and the second, 

 P. tortuosiis, and P. tristichus. The new species about 

 to be described is intermediate between these two sections, 

 in having the branches and branchlets distichous, but the 

 stem twisted at the innovations, so as to give a pseudo- 

 spiral appearance to the frond. It further differs from 

 all the known species in having the fructification attached, 

 not to the teeth, but to the surface of the frond. The 

 name here given to the plant is in allusion to the latter 

 peculiarity. 



PlIACELOCARPUS EPIPOL.EUS* (u. Sp.). 



Fronde basi teretiuscula, immerso-costata inferne sensim 

 nudiiiscula, superne complanata, ramis corymboso-pinnatis, 

 pinnis linearibus pectinato-pinnatis, ala angustissima 

 instructa, dentibus compressis latitudinem rachidis ita 

 formatae sua longitudine a-quantibus vel paululo super- 

 antibus, planis, a basi latiore acuminatis, incurvis. Cysto- 

 carpiis reniformibus breviter pedicellatis alterutra pagina 

 afiixis ; nematheciis ovato-globosis breviter pedicellatis ; 



*Somc specimens of the plant have been distributed under the MS. name 

 of P. disciger. The name epipoheiis, being of Greek derivation, is, how- 

 ever, substituted here as more suitable. 



