22 ON DR. H, A. WEDDELL's REMARKS, 



others. Be it so ; but where this is done in a manner not agreeable 

 to science, where only personal opinions and arbitrary and fallacious 

 arguments are opposed to sure observations (or " facts," as we 

 now-a-days say), then we but perform a duty in repudiating such 

 a tendency. 



Dr. W. Nylander. 

 Paris, 1st July, 1874. 



NEW BRITISH LICHENS. 



Communicated by The Rev. J. M. Crombie, F.L.S., &c. 



The following new species of British Lichens have been described 

 by Nylander, in " Flora," 1874, pp. 305-318 :— 



1. Collemopsis oblongans. Nyl. — Thallus olive-brownish, granu- 

 loso-crustaceous, thin, confluent ; apothecia bright — or red — testa- 

 ceous, somewhat concave, minute, the margin thickish ; spores 8 naj, 

 oblong, simple, or spuriously 1-septate, 0'016-30 m.m. long, 

 0"006-7 m.m. thick ; hymenial gelatine very faintly wine-reddish 

 with iodine. 



On the ground, in fissures of rocks, near Haverbrack, in West- 

 moreland (Martindale). Allied to C. Arnoldiana (Hepp.), but 

 differing in the shape of the spores. 



2. Collema terrulentum. Nyl. — Thallus olive-brown, thin, granu- 

 lose ; apothecia spadiceo-reddish, small, margined by the thallus ; 

 spores 8 n^, ellipsoid, or oblongo-ellipsoid, 5-septate, submurali- 

 divided, 0-018-24 m.m. long, 0-010-12 m.m. thick; hymenial 

 gelatine, and especially the thecse, bluish, with iodine. 



On the bark of an old ash tree at Loch Katrine, in Scotland 

 (Crombie). A small and easily overlooked species, which, unfortu- 

 nately, was but very sparingly gathered. 



3. Physcia txibacoides. Nyl. — Subsimilar to P/z. trihacia {Ag\i.), 

 Nyl., but the white soredia arranged as those of Ph. ccesia, and the 

 thalline reaction with K -I- 



On the smooth bark of young trees, near Ryde, Isle of Wight 

 (Crombie). In the specimen gathered the apothecia, unfortunately, 

 were not sufficiently developed. 



4. Iiecanoxa subexigua. Nyl. — Similar to L. exigiia., but the 

 thallus pale-greyish, subsmooth (^unequal) rimose ; spores 8 naj, 

 0-012-15 m.m. long, 0-006-7 m.m. thick. 



On maritime rocks, near Penzance, in Cornwall (Curnow). 



5. Lecanoza leucophaeiza. Nyl. — Similar to L. leucophcea, with 

 biatorine apothecia, and scarcely any gonidia present within the 

 perithecium ; but the hymenial gelatine not bluisli with iodine, or 

 only the thecse thus coloured. Thallus K f. +, yellowish. 



