Evans: HEPpPATICAE OF PuERTO RIco 543 
perianth, finally, is provided with incised wings along the lateral 
keels but is usually quite free from surface-laciniae. Ina single 
instance a very few cilia were found at the apex of the indistinct 
postical keel. In comparing S. vincentinum with S. transversale 
it is seen to be a somewhat smaller plant and to differ in its autoi- 
cous inflorescence, in its occasionally apiculate leaves, and in its 
constantly decurrent underleaves. In other respects the two 
Species are much alike. The material of S. vincentinum at the 
writer’s disposal, although including a portion of the type speci- 
men from the Hooker herbarium, is too incomplete to give a good 
idea of its various forms, and more study will be necessary before 
its differential characters are fully understood. 
MARCHESINIA 
The genus Marchesinia of S. F. Gray (1821) * was monotypic, 
being based on the single species /ungermannia Mackaw Hook. 
The genus Phragmicoma of Dumortier,} published the following 
year, was also monotypic and was based on the same species. 
Phragmicoma should therefore be considered a simple synonym of 
Marchesinia. Dumortier’s genus, however, was accepted by Nees 
von Esenbeck,t who referred to it sixteen tropical species in addi- 
tion to the single species upon which it was based. In the Synopsis 
Hepaticarum § the genus is still further enlarged by the addition 
of other tropical species until it numbers thirty-four in all. With 
the €xception of three species these are all included in the two 
Sections 7; pus (with six species) and Ptychanthades (with twenty- 
five), Phragmicoma continued to be used by writers until Gray’s 
snus was revived by Carruthers || in the original sense. When 
Trevisan ‘| made use of the genus Varchesinia he gave it practi- 
cally the characters of Phragmicoma, section Typus, of the Syn- 
3 opsis, referring to it seven species in all. The section Ptychan- 
: thoides became his new genus Ptychocoleus. Spruce recognized 
a her Marchesinia nor Phragmicoma as a genus, but his subgenus 
* Nat. Arr. Brit. Pl. I: 689. 1821 (as Marchesinus and Marchesinius). 
tComm. Bot. 112, 1822. 
t Naturg. Europ. Leberm. 3: 245. 1838. 
* 5292, 740. 1845 and 1847. 
|| Jour. Bot, 3: 301. 1865. 
T Mem. Ist. Lomb. ITI. 4: 405. 1877. 
