The Scottish Naturalist. 107 



1. Usnea prcelonga sp. nov. — Thallus pallide cinereus vel pallide, 

 cinereo-glaucescens, elongatus (pedalis et ultra), pendulus, 

 inrlatoarticulatus, minute papillosus et nonnihil rugulosus, 

 cephalodiis caraeo-pallidis frequenter obsitus ; axis centralis 

 fere filiformis (I — ) et fibrillar medullares K — C — . 



Section IV. 



Fibrillar medullares K — C — ; I — . 



1. Usnea spinosula sp. nov. — Similis U hirtcc robustae sed thallo 



et receptaculo apotheciorum creberrime aciculari-spinosis. 



Neilgherries (Dr G. Watt). 



The minute needle-like spines arise very often in groups of 

 3-6 from a common stock. 



2. Usnea endochrysea sp. nov. — Similis U hirtce, sed nbrillis 



medullaribus exterioribus rubentibus K pallide flavescenti- 

 bus, interioribus albidis K — ; apothecia mediocria testaceo- 

 lutescentia fibrilloso - ciliata ; sporae, .009-. 01 1 x .0055- 

 .007 mm. 



In Alabama American bor. (Mrs Hawley). 



3. Usnea subcornuta sp. nov. — Similis U coniutce sed fibrillar 



medullares K — , I — . Stipites et rami sordide rubiginei. 



In Madeira (J. Payne). 



4. Usnea mutabilis sp. nov. — Similis U. cornutce sed nbrillis 



medullaribus exacte ut in Usnea endochrysea. 



In Alabama Americas bor. (Mrs Hawley). 



The stems and branches are thickly sorediate, but the termin- 

 ations of the branches are only slightly arcuate, and are not 

 continuously sorediate. I have another from the Neilgherries 

 by Dr G. Watt, similar in constitution to the above as regards 

 the medullary fibres, but much more robust, and with prominent 

 soredia. This I leave in abeyance meanwhile. 



Usnea Thomson/ sp. nov. — Similis fere omnino U. ceratince robus- 

 tae sed sporis amplioribus, .013-.017. x 009-.011 mm.; para- 

 physes irregulares, graciles, non bene distinctae. Iodo gel. 

 hym. caerulescens dein vinose fulvescens. Thallus flaves- 



