86 THE .TOrR-N'/VL OP EOTATs^T 



covered only by the persistent cuticle. — On the stems of the" same 

 twigs was the thick convex Lopliodermium cladopliilmn Rehm 

 ( = Sporo)}ieqa cladopliila Duby), o£ which L. melaleucum should 

 probably be considered merely the leaf -form. There are now many 

 instances known where the same fungus assumes on the leaves a less- 

 developed and simpler form than on the stems. 

 (To be continued.) 



HHACOPILOPSIS TRINITENSIS E. G. Brttt. & Dixon. 



By H. N. Dixon, M.A., F.L.S. 



(Rhacopilopsis Een. & Card, in Rev. Brvol. xxviii. 47 (1900)). 

 Syn. Bimorplidla (C. M.) Ken. & Card. 'in Bull. Soc. Roy. bot. 

 Belg! xli. 101 (1902-3), Hypnum sect. Dlmorphella CM. in Flora, 

 1886, p. 523. 



This genus was based on an African moss which later proved to 

 be identical with Ili/pmtm FechueUi C. M. Because C. Mueller 

 referred it to a new section (Dimorphella) it was later described 

 as a genus, and it is as DimorpJieUa that Brotherus listed and figured 

 the African species (Engl. & Prantl, PHanzenfam. ii. 1083 ; fig. 770). 

 Subsequently Cardot referred two specimens from French Guiana, 

 collected by Gouverneur Re}^ in 1900, to Fhacojrilojjsis, as varieties of 

 the African Dimorphella Pecliuclii. Specimens of. these were sent 

 by Mons. I. Theriot to Mrs. Britton, who found on comparison that 

 they were at least very close to the Trinidad 2:)lant described in 1851 

 by C. Mueller as Hypnnm triuitense (Syn. Muse. ii. 284), subse- 

 quently placed by Mitten {m Musci Austro-americani) under Fcfro- 

 potliecium. 



Further examination of the American plants by Mrs. Britton and 

 Mr. R. S. Williams, and of the plants in the British collections by 

 myself has led us to the conclusion that the African plant cannot be 

 separated from the American H. frinitense. This, too, was Mitten's 

 o])inion, for I find in the Kew^ Herbarium two West African speci- 

 mens in Herb. Hooker — viz. '* Bagroo R., W. Africa " ; and " N. 554 ; 

 Banks of the Nunn, Sept. 1860 ; G. Mann " — labelled " Stereodon 

 trinitensis (C. Mull.) " by Mitten. Cardot also held a similar view, 

 for he referred the French Guiana specimens already mentioned to the 

 two varieties of FimorpheUa Fechuelii (as the plant was then 

 known) described by him in Rev. Bryol. xxxvi. 50 (1909), based 

 upon specimens from the Belgian Congo ; without of course suspect- 

 ing any relationship to the alread}^ described American species. He 

 repeats the same opinion, viz., that the ]:)lants from French Guiana 

 are conspecific with the African species, in the Mousses de Mada- 

 gascar, p. 468. 



One character that at first appeared to constitute a difference 

 between the American and African plants was the more constant 

 presence in the former of the pellucid, inflated alar cells appearing on 

 many of the leaves, usually on one side only of the base. These, 

 however, if less constantly present in the African plants, are quite 

 characteristic ; I have measured them up to 10 /.i, 12 /i, and 14 /u. ; 



