2 THE joiir:n^al of botany 



Rami sjBpe usque ad tres ex eodem nodo orientes, 1-2 in loco 



ramuloruin suppressorum, ut videtur, saepe abbreviati et inchoati et, 



quum quidem elongati, non raro verticillos rudimentarios proferentes. 



Ramuli pauci, plerumque 2-3 tantum in utroque verticillo, 



normaliter sinipliciter-furcati sed aliquando duplicato-fureati. 



Latercdes radii secundarii singulares, perspicue breviores radiis 

 mediis, ssepe inchoati, brevissimi et inperspicui apud nodos antheridia 

 proferentes. Radii secundarii unicellulati, apicibus variantibus a 

 forma acuminata ad formam vel rotmide-acutam vel obtuse-mucro- 

 natam. 



Oogonia et antheridia vel ad eundem nodum vel ad diversos 

 nodos producta. Oogonia vel singularia vel 2-3 aggregata, 800-850 }x 

 longa, 6-10-680 p. lata. Cellulse spirales 7 convolutiones exhibentes 

 et versus apices tumifacientes, coronula decidua, c. 60 fx alta, c. 80 /x 

 lata. 



Oospora 475-500 /x longa, 425-450 fx lata, 330 fx crassa, 7 strias 

 tenues exhibens alis promulis versus apicem. Membrana rubra aut 

 rubra-fulva, spissa, semi-rigida, et translucens, scabra perpusillis 

 tuberculis, et minimis granulis decorata. 

 Antheridiu?)i 575-675 fj, diametro. 



iV^. spanioclema is closely allied to N.flexilis, being monoecious 

 with branchlets normally once f m'cate and the ultimate raj^s one-celled ; 

 its frait also is very similar. It differs, however, from that species 

 in its fragile and delicate habit, the extraordinary paucity and irre- 

 gular development of its branchlets and secondary rays, and in its 

 occasional second furcation. When, as often happens, the secondary 

 rays are suppressed or only rudimentarj^ the antheridia have the 

 appearance of being borne on long stalks. In the frequent absence of 

 lateral secondary rays the plant bears a resemblance to K. mono- 

 dactyla Braun, a sub- tropical dioecious plant described and figured in 

 the Fragmente. The oogonia are frequently produced at the base of 

 the whorls, and their enveloping cells are divergent and much dis- 

 tended at the apex. The membrane shoAvs the peculiar mottled 

 surface with wart-like protuberances which are characteristic of 

 N. opaca and N. flexilis^ but besides this it possesses a delicate 

 decoration which is absent in those two species. This decoration 

 consists of exceeding minute granules which are at first linear in 

 their arrangement, but at a later stage assume a reticulate form. 



It will be interesting to ascertain whether the plant occurs in other 

 parts of Ireland. In the Fanad Peninsula it appears to be confined 

 to Lough Shannagh. 



Explanation of Plate 551. 

 1,2. Plant natural size. 



3, 4. Branches with bianchlets showing short solitary and rudimentary secondary 

 rays and conspicuous scars left by fallen antheridia and oogonia, X 10. 



5. Oogonium, X 30. 



6. Oospore, showing ridges with broad flanges, X 30. 



7. Piece of membrane showing wart-like protuberances and minute granidar 



decoration, X c. 200. 



8. Piece of membrane showing disposition of granules, X c. 800. 



