and degree of dehiscence of the capsule ; as also of the structure of the 

 elaters, and their persistence or decidence ; the importance of which in 

 the separation of genera and tribes has long been acknowledged. 4°, 

 the number of the sexual, and especially of the male, organs, which is 

 very constant in many genera, and varies through ascertainable limits 

 in all others. Thus the cf florets, or bracts, are monandrous in all 

 CephalozicB, Kantm, Antlieli^^B , &c.; diandrous in the great mass of 

 LejeunecB, and monandrous only in two or three small sections of that 

 extensive g^ius ; diandrous — very rarely triandrous — in Frullania ; ■ 

 polyandrous in some Plagiochila, TylimantM, ScapaniiB and Gottschece ; 

 &c. &c. The number of pistilhdia varies through wider Umits, and in 

 many genera the flowers are polygynous ; in Lejeunea, however, they 

 are constantly monogynous ; in Fndlaiiia, very mostly tetragynous, 

 although one or other of the four pistillidia may remain undeveloped, 

 thus reducing the actual number to two or three. Characters derived 

 from the number and structure of the sexual organs do indeed figure in 

 the descriptions of a few genera framed by Nees, Grottsche, &c., but they 

 deserve accurate determination in all. The relative position of the cf 

 and $ flowers affords as important characters for discriminating species 

 in Hepaticae as in Mosses, and is ia every case necessary to be ascer- 

 tained. 



The species I have united under the name Cephalozia are all so 

 closely allied by important characters that they must ever stand near 

 each other in a natural arrangement. In the introductory portion of 

 the memou' will be found a full exposition of the reasons which have 

 induced me to combine them into a single genus. To some minds cer- 

 tain of what I have considered mere subgenera may have the value of 

 distinct genera. Perfect agreement on this head is perhaps unattain- 

 able ; but it is obviously a mere question of names whether we choose to 

 write (for instance) Cephalozia vionodactyla, or Cephalozia (Zoopsis) mo- 

 nodactyla, or Zoopsis vionodactyla ; so long as we do not lose sight of the 

 close relationship of the species to typical Cephalozia. 



In the citation of authorities I have followed the rule of Elias Fries ; 

 " Ofver vexternes namn " in the Botaniska TJtfiygter iox (I think) 1845: 

 in always citing the writer who first named and described (or published 

 named specimens of) a species as the authority for it. In April, 1846, 

 Dr. Camille Montague shewed me a translation he had just made of 



