ON GENERA AND SPECIES. 57 



OBS. The genera founded by Sir William Hooker, of 

 which there are five, are marked with an asterisk, and the 

 number of species named and described by him in the 

 " Species Filicum " amounts to about 600. 



In a notice at the end of the fifth volume of the " Species 

 Filicum," he states, that " if his life and health be spared 

 to him, he intends to accomplish a volume to be entitled 

 * Synopsis Filicum,' to contain brief characters of the sec- 

 tions, genera, and species of Ferns, general habitats, and 

 references to the ' Species Filicum/ omitting all really 

 dubious species, and including the sub-orders Osmundacece, 

 Marattiacece, and Ophioglossacece" which it is hoped will 

 form ** a useful vade mecum for the travelling botanist, 

 and the cultivator of Ferns, and for ready consultation in 

 the herbarium." 



Only one part, with the preface of this work, consisting 

 of twenty-two pages, was printed at the time of the 

 author's death (which took place in August, 1865) ; the 

 remaining manuscript was placed in the hands of Mr. 

 J. G. Baker, who, shortly after Sir W. Hooker's death, 

 received the* appointment of Assistant Curator in the Kew 

 Herbarium, and who has carried out the author's views, 

 forming a volume of 482 pages, which was published in 

 1868, accompanied by nine coloured plates illustrating the 

 characters of the genera, of which there are seventy-five. 



In the arrangement of the tribes and genera this work 

 does not differ materially from the " Species Filicum :" the 

 number of species described of Gleicheniacece and Poly- 

 podiacece amounts to 2,122, being 279 less than the 

 " Species Filicum," while 106 are enumerated under the 

 sub-orders Osmundacece, Marattiacece, and Ophioglossacece, 

 thus making a total of 2,228 species, being chiefly founded 

 on specimens in the Hookerian Herbarium, which, at the 



