34^ Wheldon : Key to the Harpidioid Hypna. 



45. Acumen flcxuosc, longly subulate : alar cells very prominent 

 and convex, large, hemispherical : cells 12 times as long as broad, 

 median 72 /it, upper 78 /< long (D. adunciis var. cyrtopteron). Acumen 

 subcarinate, not flexuose : alar cells less projecting : cells a little shorter 

 {D. adiinciis var. pseiido-Sendtneri). 



46. Alar cells coloured purple-brown, their walls thick, often filled 

 with brown granulations : nerve 30-45 /i : median cells 60-66 yu : 8-10 

 times as long as wide {D. adunciis var. falcaliis f. riijoalaris). Alar 

 cells not rufous-brown (47). 



47. Leaf base broadly ovate-lanceolate : acumen fine but hardly 

 filiform (48). Leaf base narrower, almost lanceolate : acumen with a 

 piliform subule : cells a little shorter, ffexuose, rather dense {D. adunciis 

 var. falcatus f. subpiligera). 



48. Auricles hyaline {D. aduncus var. falcatus). Auricles obscure, 

 filled with granulations and often badly delimited {D. aduncus var. 

 falcatus f. littoyalis). 



49. Leaves rather small : median cells comparatively short and 

 wide (30-40 /^ long) : apicalleaves ovate-deltoid, shortly acuminate (50). 

 Leaves larger : median cells longer and relatively narrower, 35-50 /t 

 long (51). 



50. Procumbent, often with many irregular slender branches : 

 leaves lax, erect -patent, only lightly secund above [D. polycarpus). 

 Submersed or in drier situations in depressed patches, very slender : 

 branches long, almost filiform : leaves very distant, patent : habit of 

 Amblystegium Kochii (D. polycarpus var. attenuatus) . 



51. Leaves imbricate, the upper ones julaceously appressed, with 

 sliort points (52). Leaves ovate oblong to oblong-lanceolate, 2-5 mm. 

 long : the apical ones not markedly julaceously appressed except in the 

 apical bud (53). 



52. Terete terminal portion of stem elongate cylindrical [D. poly- 

 carpus var. pungens). Terete terminal portion of stem ovate clavate 

 [D. polycarpus var. clavatus). 



53. Leaves spreading, flexuose, 2-3 mm. long, oblong, insensibly 

 and longly acuminate subulate, subule flexuose and twisted {D. poly- 

 carpus var. peyacuminatus) . Leaves oval or ovate, erect patent or 

 subsecund, not subulate (54). 



54. Leaves uniform, large (5 x 2-5 mm.), very distant, broadly 

 oval, loosely erect patent : plant soft and weak, nearly simple : auricles 

 very indistinct : nerve short (D. polycarpus var. imniersus). Leaves 

 more or less distinctly dimorphous, shorter and broader upwards, ovate- 

 acuminate (55). 



55. Plant rather robust : stems regularly and often rather closely 

 pinnate (56). Plant usually more slender, green, irregularly pinnate 

 or branched, sometimes subsimple (57). 



56. Yellowish, rather rigid, 8-15 cm. high (D. polycarpus var. 

 intermedins f. penna). Pale green, elongate and slender (up to 25 cm. 

 long): St. leaves very distant, heterotropous : median cells up to 75 /i 

 long, much shorter and laxcr towards l^ase : nerve, about half way (D. 

 polycarpus var. intermedins f. inundata). 



57. Alar cells distinct : leaves distant (D. polycarpus var. inter- 

 niedius f. laxa). Alar cells loss distinct, sometimes almost obsolete: 

 elongate and floating, leaves very distant, subfalcate, apical cusp falcatc- 

 secund {D. polycarpus var. intermedins f. laxifolia). 



{To be continued). 



Notes on a Collection of Hepatics from the Camcroons, W. Coast of 

 Africa, by W. H. Pearson, is the title of Manchester Museum Publiration 

 No. 84 (6 pp., 2/-). 



