306 L'Abbe E. Coemans on the Cladonise 



the flower is monopetalous, theoretically it is dipetalous, the half 

 of it only being present in them ; for when, as in the yew, we 

 have the whole present, we then find a petal or scale on each 

 side, opposed to each other at the base of the disk, which only 

 begins to grow after the petals or scales have attained their full 

 dimensions. 



It may be that I am wrong in referring the claret-coloured 

 crust of petaloid texture which I observed between the scales in 

 Wellingtonia to the bract, and that it has not this relation at all, 

 and also that cypresses have truly no bract. Should that be so, 

 it would furnish a good distinctive character for separating the 

 cypresses from the pines. 



I owe some apology to the reader for desiring to give ad- 

 ditional explanation on an opinion expressed so recently ; but 

 in all new lines of thought the mind is at first apt to veer back- 

 wards and forwards as new objections or doubts suggest them- 

 selves; and although it may not be better for the scientific 

 reputation of the thinker, it is certainly better for the progress 

 of truth, that these vibrations should be candidly acknowledged, 

 so that the real weight of the objections may be estimated by 

 fresh and impartial minds. 



XLI. — Notulce Lichenologica. No. X. 

 By the Rev. W. A. Leighton, B.A., F.L.S. 



CLADONIyE ACHARIAN^. 



The Rev. PAbbe Eugene Coemans, of Gand, Belgium, has re- 

 cently published, in the 'Bulletins de 1' Academic royale de 

 Belgique,' ser. 2. t. xix., the results of an investigation of the 

 herbarium of Acharius, so far as regards the CladonicB. The 

 herbarium of Acharius is preserved in the Museum of the Uni- 

 versity of Helsingfors; and its arrangement is precisely that of 

 the latest work of this author, the ' Synopsis methodica Liche- 

 num,' 1814. The collection comprises 43 genera and about 

 980 species, besides innumerable varieties. The localities 

 whence the specimens have been gathered are generally noted ; 

 but the specimens themselves are often small, and with respect 

 to those communicated by others we have no other clue to 

 whence they came than the peculiar handwritings of the corre- 

 spondents of the illustrious lichenographer. The Cladonice con- 

 stitute about a fifteenth part of the collection, and, although not 

 the most beautiful portion, is nevertheless exceedingly precious, 

 and contains a great number of the types of Florke, Schserer, 

 and Leon Dufour. 



The object proposed in this revision of the Acharian herba- 



