Rev. W. A. Leighton on the British Umbilicarise. 277 



rearraiic:cs the various forms into eight species. British authois, 

 as Purtoii, Midi. Fl. (1817), Hooker, FL Scot. (18.21), and 

 Greville, Fl. Edin. (1824), adopt Gyrophora as the genus. Fries 

 in all his works resolutely maintains the original name, Umbili- 

 caritty of Hoffmann. Eschweiler, Syst. Lich. 1824, places Gyro- 

 phora in company with Soiorina, Ach., Dermatocarpon, Eschw., 

 Endocarpon, Hedw., Capitularia, Eschw., and PeltideOj Ach., in 

 his Cohors V. Dermatocarpece. Wallroth, Crypt. Germ. (1831), 

 makes Unihilicaria a section of his genus Graphis, considering 

 the affinity in structure of the apothecia with those of the Gra- 

 phidea, hinted at by Eernhardi, Florke and DeCandolle, to be cor- 

 rect and well founded. Hooker in Brit. Flor. (1833) follows the 

 arrangement of Fee (Cryptog. Ecorces, 1824) into Gyrophoi'a and 

 Umbiiicaria, from the different external aspect of the apothecia. 

 His distribution of the species differs somewhat from that of the 

 ' Lichenographia Britannica.' Dr. Taylor in Flora Hibernica 

 (1836) again unites the two genera. Merat in Flor. env. Paris 

 (1836) puts U. pustulata into a new genus called Lasallia. Che- 

 vallier (Flor. Paris, 1836) and Flotow (Lichenes Flor. Siles.,1850) 

 separate Umbiiicaria and Gyrophora, Tuckerman, Syn. Lich. 

 Ainer. (1848), retains the entire genus Umbiiicaria, Hoffm., with 

 a modified generic character. 



Massalongo (Licheni Crostosi, 1852) retains Umbiiicaria, 

 Hoffm., for the generality of the species, but refers U pustulata 

 to a new genus, Macrodictya, his distinctions being taken from 

 the dissimilarity of the sporidia. In his Memorie Lichenog. 

 (1853) he rejects his new genus Macrodictya and adopts Merat's 

 Lasallia. In his Systema Lichenum Germanise (1854) Koerber 

 separates Umbiiicaria (pustulata) from Gyrophora, Nylander in 

 his " Nouvelle Classification des Lichens " in Mem. Soc. des Sc. 

 Nat. de Cherbourg (1854 & 1855), retains the original and com- 

 prehensive genus of Hoffmann, Umbiiicaria, as the type of his 

 tribe Gyrophorem. 



From the preceding summary it is seen, that whilst the plants 

 have retained their relative position as members of a closely con- 

 nected group, considerable difference of opinion has existed as 

 to the name which should be assigned to it, and whether Umbi- 

 iicaria pustulata should be included in the same genus, or form 

 a distinct genus by itself. From the identity of structure both 

 of thallus and apothecium, I incline to think that it ought, with 

 the other plants, to constitute one and the same genus, and that 

 the original name of Hoffmann, Umbiiicaria, which appears to 

 have been changed from no really substantial scientific reasons, 

 should be restored to it. 



The learned authors of the ' Lichenographia Britannica ' com- 

 plain, and with justice, that the genus has been divided into too 



