124 Historical Sketch of Improvements in [Aug. 



of a footstalk ; of which, at present, only one species is known, 

 D. rupestris, found in Germany. Berl. Mag. Naturf. Fr. 



Lichenes. — A descriptive monograph of the genus trypothelium, 

 by Professor Acharius, is inserted in the Mem. Mosq. ; this 

 monograph describes 10 species. And he has given (Limi. 

 Trans, xii. 35) a monograph of 2 genera, Glyphis and Chiodec- 

 ton, with an enumeration of their species, which were found on 

 the bark of some ti-opical trees. He has described also the sub- 

 family caliciodea, which he divides into those having the apo- 

 thecia sessile, as limbora containing 9 species ; cj'phelium, 18 

 spec, or having the apothecia stipulated, as calicium, 41 spec, 

 concocybe, 4 spec, and has figured 37 of the species in the 

 Stock. Trans, continued from the preceding volumes. 



Hi/poxi/lL — De Candolle has lately divided all the known 

 genera into 3 tribes; 1. Sphaeria?, pulp very abundant, base 

 fleshy, or corky, not lichenoid ; containing sphaeria, rhizomor- 

 pha, ngematospora, and stilbospora. 2. Xylomas, pulp not 

 abundant, base fleshy or corky, not lichenoid, containing poly- 

 stigma, xyloma, asteroma, hypoderma and hysterium. S. 

 Lichenoides, pulp not abundant, base powdery, lichenoid, 

 containing opegraphia, verrucaria, and pertusaria. Mem. 

 Mas. iii. 



In a subsequent paper he has examined the parasitic fungi, 

 and subdivides xyloma into 3 sections, spiloma containing 14 

 species ; microma, 22 spec. ; and decroma, 5 spec. He enume- 

 rates 6 species of asteroma, 3 of polystigma, and subdivides 

 stilbospora into 2 sections, stilbospora containing .5 spec, and 

 hygrocliroma 2 spec. Of these parasitic fungi he has figured 10. 

 Mem. Mvs. iii. 



A new British species of rhizomorpha having been found at 

 Derby by Mr. Booth, Sir J. E. Smith lias described and figured 

 it under the name and character of rhizomorpha meduUaris; cy- 

 lindrical, very much branched, snow-white ; internally cellular, 

 yellowish. Lnui. Tr. xii. 



Fungi. — A most extensive German work upon fungi has lately 

 been brought to England, namely, Das System der Pilze unci 

 Schwamme, by E. G. Nees von Esenbeck; in 2 vols. 4to. with 

 44 plates, containing 366 figures to illustrate the genera. 



Dr. Esenbeck is an advocate for the successive transition of 

 natural substances, and of their passage from one species to 

 another. Accordingly, he usually designates one species as 

 the type of each fiimily, and then shows the several shades of 

 difference by which this species passes into the types of the 

 other natural families. He divides fungi into 2 grand divisions, 

 vegetabilia mycetoidea (angiocarpii Pers.) and fungosa (gym- 

 nocarpii P.) The mycetoidea are subdivided into 3 kingdoms : 

 1. protomyci, which includes the uredines, xylomata, and seve- 

 ral other fungi akin to them, 2. naematomyci, including the mu- 



