270 DB. LAUDER LINDSAY ON ARTHOISIA HELASPKBMELLA. 



found it, and always considered it a Lichen, Mr. Berkeley thinks 

 it certainly a Peziza of the section Patellea : and Mr, Churchill 

 Babington inclines to this view. Mr. Leighton thought at first 

 that it was Lecidea nigritula^ Nyl. *, but ultimately was disposed 



to consider it a Fatellaria My own idea is that it is a 



Patellaria. True Pezizas have not septate sporidia, nor sporidia 

 of a dark colour ; and the structure is more leathery than that of 



any Peziza I know of. The plant has a wide range, as I find 



it also amongst some Pungi from Massachusetts. Mr. Babington 



suggested a possible affinity with Biatora campestris, Fr.f 



The hymenium is tinged blue with iodine I used only a 



weak solution of iodine, and observed a very manifest hlue tinge 

 to be produced by it. There are several Fungi in which the same 

 reaction occurs ; so that this test is no longer conclusive between 



Fungi and Lichens The plant was collected in 



the neighbourhood of London ; and, if I recollect rightly, close to 

 Weybridge, in Surrey." Nylander, the first living authority on 

 the classification and nomenclature of Lichens, and the author, 

 moreover, of a monograph of the genus ArlhoniaX, regards this 

 plant (1865) as an Arthonia. For myself, I do not feel satisfied 

 either with its position in the genus Arthonia, if it is to be re- 

 garded as a Lichen, or with its position among Lichens. I 

 prefer to refer it, provisionally at least, to the Fungo-lichenes \ 

 classing it under the head of Lecidiella, or some similar name, to 

 signify its resemhlance, quoad its apothecia, to the Lichen-genus 

 Lecidea. 



The specimens which I suhmitted to examination were three in 

 number — two from Weybridge, and one from Massachusetts. In 

 all three the plant affects striated or grooved, weathered wood, 

 apparently fabricated timber. There is no visible thallus — the 

 apothecia and pycnides, which constitute the plant, being seated 

 generally in the furrows of the wood, having thus a linear arrange- 

 ment (in rows). (PL VI. figs. 1, 2.) 



The apothecia (fig. 2, a) are lecideiform, generally exhibiting 

 a roundish, flat, thin disk, with a very thin, frequently wavy or 

 corrugate margin, both of a pitch-black colour ; but occasionally 



w 



* The plant certainly has a close resemblance to some athalline forms of Le* 

 eidea nigritula^ l^jLj and i. mt/riocarpa^ DC, which also occur on old fabri- 



cated timber. 



Mougeottii 





ArthoWa," MAn. de la Soci^^ Imperiale des Sciences 



I 



Cherbourg 



