248 Wheldon : Key to the Harpidioid Hypna. 



cordate-triangular base, rather suddenly narrowed and finely acuminate, 

 branch leaves more or less flexuose when dry : alar cells variable, colour- 

 less or yellowish, usually hyaline, their walls but little incrassate (8). 

 Branches more irregular and distant, often elongate, ascending and stem- 

 like, subfasciculate : stems scarcely tomentose, with few rhizoids, and 

 scattered paraphyllia : leaves of stem and branches less strongly 

 dimorphous, those of stem from a narrower, more elongate base, more 

 gradually narrowed to a wider acumen : branch leaves hardly flexuose, 

 more rigidly falcate-secund : cells longer, texture more solid : auricles 

 coloured, often opaque, with more incrassate cell walls (10). 



8. Greenish, yellowish or fulvous, ochraceous below, more or less 

 closely plumosely pinnate : stems with dense rufous tomentum (C. 

 glaucum). Green : leaves more rigid, and more strongly nerved (9). 



9. Lively light green, pallid and often lime encrusted below, often 

 creeping and irregularly pinnate : rhizoids abundant on undersides of 

 stem : plant of wet calcareous rocks and tufa (C. glaucum var. fontanum). 

 Dusky olive green, tall (10-20 cm.), stout or rather slender, rather 

 closely and regularly pinnate above, and often throughout : stems with 

 many paraphyllia and a few rhizoids, sometimes denuded below : leaves 

 rather narrower, approaching the ' falcatum ' shape, and branches also 

 stout : nerve 76-82 /< wide at base (C. glaucum var. siibiryigatum) . 



10. Dark to blackish-green : stems with very few scattered slender 

 paraphyllia or none, and no tomentum, often denuded of leaves below, 

 and bristly with the persistent remains of the very stout nerves ; nerve 

 very thick (at base 100-130 /<), remaining very stout throughout, and 

 percurrent or lost in the point (C. irrigatmn). Nerve more slender and 

 more tapering (60-80 /n at base), less engaged in the acumen : stems not 

 denuded below (11). 



11. Very tall (10-25 cm. high), bright yellow or ochraceous, with 

 the colour and habit of a very robust Drepanocladus Wilsoni : irregularly 

 pinnate, the branches often long and ascending at an acute angle : leaves 

 dense, falcate-secund, their points often flexuose-spreading, 2-3 mm. 

 long : nerve 60-70 jj, wide (C falcatum var. speciosum). Less robust, 

 and shorter (5-15 cm.), dusky green, yellowish -green to brown (12). 



12. Tall or short, very variable, but usually paler and less rigid 

 than the next : leaves with a comparatively short and wide acumen, 

 2-2.5 rnm. long (C. falcatum). Short and stout (5-10 cm.), fuscous- 

 yellow above passing immediately to brown and black below : leaves 

 about 2 mm. long, very densely imbricate, circinate-secund, with a 

 longer and finer acumen : nerve solid, brown, 70-80 /j, wide at base : 

 resembles in habit Limprichtia revolvens (C. falcatum var. alpinum). 



(To be contimied). 



As Hull Museum Publication No. 96, an index of the publications 

 48 to 95, has been issued, which will be useful to those using these publica- 

 tions. The first 47 publications had previously been indexed. The 

 index is not a wonderful example of typography, but we suppose this is a 

 sign of the times. 



Leicestershire, by G.N. Pingriff, Cambridge University Press ; 

 164 pp., 3/6 net. W'c regret that the notice of this useful publication 

 has been delayed. Its appearance aids towards the completion of the 

 well-known Cambridge County monographs. For the articles on natural 

 history and geology, with which we are more concerned, the author is 

 indebted to the British Association Guide to the district. There is a 

 fine series of illustrations. 



