304 Alexander W. Evans, 



M. androgyna of Weber^^ is actually Conocephalum conicum, and 

 the Linnaean name has been applied by other writers to such 

 distinct species as Preissia quadrata (Scop.) Corda and Rehoulia 

 hemisphaerica (L.) Raddi. 



Lehmann and Lindenberg's conception of M. androgyna Sw. 

 was based on specimens collected by Swartz in Jamaica. 

 Although they considered these specimens identical with those 

 collected by Collinson they did not take up the name M. 

 androgyna for the species, probably because the original M. 

 androgyna L. was an aggregate. They described it instead under 

 the new name M. Swartsii. The female receptacle, according 

 to their account, is unsymmetrical, hemispherical, and subentire 

 or obsoletely lobed, the lower surface and the stalk being villous. 

 They state further that the upper surface of the thallus is green 

 with many large pores bordered with white, and that the lower 

 surface is brown with scales in the median portion ; and they 

 suggest that the male receptacles of Swartz's description may 

 have been cupules only. So far as the descriptions go M. 

 Swartzii and, consequently, AI. androgyna Sw. do not differ in 

 any essential respects from M. chenopoda, and the authors of the 

 Synopsis are probably correct in citing these two species as 

 synonyms of M. chenopoda. This view is supported by a frag- 

 mentary specimen in the Taylor herbarium, labeled M. Szvartzii 

 by Lehmann, which apparently represents M. chenopoda, although 

 a positive conclusion can hardly be reached without sectioning 

 the material. 



A further difficulty in disentangling the synonymy is, how- 

 ever, encountered. Although Lehmann and Lindenberg con- 

 sidered Swartz's and Collinson's plants identical, this opinion 

 was not shared by the authors of the Synopsis Hepaticarum. 

 In quoting M. Swartsii as a synonym of M. chenopoda they 

 take pains to exclude the Dillenian /. j altogether, although 

 /. ^A and /. jC are definitely quoted by the authors of M. 

 Swartzii in citing M. androgyna Sw. as a synonym of their spe- 

 cies. Fortunately Collinson's material is preserved in the Dil- 

 lenian herbarium and throws a little light on the subject. It 

 was studied by Lindberg, who reached the conclusion that it 

 represented a distinct and undescribed species. This he pro- 

 posed as new under the name M. Dillenii Lindb. He assigns to 



" Spic. Fl. Goettingen. 168. Gotha, 1778. 



