THE NATURAL HISTORY OF THE BRITISH DIATOMACEJE. 71 



boides (sporangia! form of Dr. Lewis). The curious decussating 

 stria? of N. rostellum (in fact, no kind of stria? are figured) are not 

 shown. In the description they are stated to he indistinct, 80 in "001 ; 

 under a power of 500 diameters they are easily resolved, and are 

 certainly not more than 55 or GO in "001.* 



Having thus alluded to the defects in the plates, we proceed to 

 the more agreeable task of calling attention to their merits ; 

 excepting those just named, and two or three others, they are far 

 more correct than those in the Synopsis. We would particularly 

 draw attention to the following forms : — N. liebes = N. obtusa, Sm. 

 N.rostrata= N. tumens, Sm. (the figure in the Synopsis is totally 

 unlike the actual form), N~. alpina, N. latiuscula = N . patula, 

 Sm., N. nobilis and N. major are all admirably represented. In 

 concluding these brief and imperfect remarks on Dr. Donkin's 

 undertaking, we beg to express our best wishes for its success, and 

 hope the publication of the parts will now proceed uninterruptedly. 



F. KITTON, Norwich. 



* We happen to know that the principal cause of the delay in the publication of 

 the parts has been owing to the difficulty of obtaining satisfactory drawings. 



ADDITIONS TO THE LICHEN FLORA OF GREAT 

 BRITAIN. 



By Dr. J. Stirton. 



1. Pyrenopsis hcemalea. Smrf. — Ben Lawers, July, 1871. 



2. Lecidea botryiza. Nyl. Sp. nova. — Thallus cinereo-virescent, 

 squamuloso-pulverulent, thin (K — C — ). Apothecia small, simple or 

 aggregate, prominent, almost spherical, pale-brown to dark-brown ; 

 spores 8, colourless, elliptical, simple (-008 X -004 m.m.) ; hyme- 

 niurn colourless, pellucid ; paraphyses not discrete, apices colourless ; 

 hypothecium thick, dense, brownish-black ; gelatina hymenea creru- 

 lescent then vinous-red with iodine. Ben Voirlich, 1871. 



3. Lecidea Brayeriana, /. ochrodes. Nyl. — Glen Callater, 1872. 



4. Lecidea cupreiformis, var. lecanodes. Nyl. — Apothecia spuria 

 lecanoroidea. Ben Lawers, 1871. 



5. Lecidea subincompta, /. ozibata. Kyi.— Ben Lawers, 1871. 

 C. Lecidea persimilis. Nyl. — Lich. Scand., p. 236. 



Thallus whitish, visible here and there, granular ; apothecia at 

 first small and very concave, afterwards flat and expanded as^well as 

 enlarged. I am inclined to refer Lecidea scapanaria (Carrington) 

 to this Lichen. 



Ben Lawers, 1871. Carlochan, 1873. On JungermannicB . 



