MARINE ALGM OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 81 



lateral veins. From P. pleurosporum it differs in being very proliferous, and in the 

 sori not being confluent over the costa. The sori, in fact, resemble those of Hypo- 

 denticulatum as figured in Kiitzing's Tab. Phyc.,xvi. tab. 15, 1 ( = Pteridium 

 ., J. Ag.). De Toui divides the genus Pteridium into three sections, the 

 first of which contains species with a "frons teretiuscula," which our plant has not; 

 the second section has an obsolete costa ; and the third shows a difference in the form 

 and disposition of the cortical cells, which cover the costa and the frond, when seen in 

 surface view, besides having lateral veins. Our plant therefore falls into none of these 

 sections. It may be thought that P. proliferum approaches more nearly to Hypoylos- 

 sitm ; but from that genus it differs in being branched, as well as proliferous. From 

 Erythroglossum it differs in having proliferations emerging from the costa, and in the 

 similarity in form and size of the cortical cells of costa and frond. It differs from 

 Reinsch's Delesseria condensata in having a much less strongly marked costa, and in 

 being proliferous. 



26. PTERONIA PECTINATA, Schmitz ( = Polysiplwnia pectinata, Hook, and Harv.). 

 Scotia Bay, South Orkneys, July and December 1903. 



Geographical Distribution. Cape Horn, Falklands, South Georgia. 



Reinsch (loc. cit., p. 374), in his note on this plant, says he believes it had never been 

 figured. But he had overlooked the coloured figure in Harvey's Nereis Australis, 

 tab. xxvii., which represents part of the thallus of a specimen from the Falklands 

 collected by Mrs Sulivan, spelt " Sullivan" on the original in Herb., Kew, where there 

 is an original drawing showing the structure, habit, and cystocarp. One of the Scotia 

 specimens was growing attached to Hydrolapathum stephanocarpum. 



27. PTILOTA CONFLUENS, Reinsch. Scotia Bay, South Orkneys, October 1903. 

 Three incomplete plants without fruit. 



Geographical Distribution. South Georgia. 



This species is described and figured by Reinsch (loc. cit., p. 376, tab. iii. figs. 5-9). 

 His figure of a portion of the frond, being reduced to one-third its natural size, is not 

 very helpful in determination. The figures of the structure, combined with the clear 

 diagnosis and remarks, are, however, enough to enable us to recognise our plant as 

 P. confluens. Reiusch remarks that the axillary cell in his specimen has almost dis- 

 appeared. In our plant it is still quite clear. 



28. CRYPTONEMIA LUXURIANS, J. Ag. Off Brazil, same locality as No. 3. 

 Geographical Distribution. Brazil, Martinique. 



29. FLORIDEA, A. and E. S. Gepp in Journ. of Bot., xliii., 1905, p. 193, tab. 472, 

 figs. 1, 2. 



Frons cartilaginea plana, 23 cm. lata, irregularitcr lacerata et fenestrata laevis, 

 stratis duobus contexta ; cellulis iuterioribus majusculis (35-70 n long., 15-25 /x lat.) 



irregularibus rotundato-angulatis vel plus minusve axin versus perpendiculariter elon- 

 VOL. III. n 



