Evans : Hepaticae of Puerto Rico 161 







This species agrees with B. insnlaris in its inflorescence, but the 

 lobes of its leaves and bracts are sharply pointed. The bracteole 

 is also said to be emarginate or even bifid, but the figure of 

 Schififner does not show this condition clearly. 



PTYCHOCOLEUS 



The history of Trevisan's genus Ptychocolcus has already been 

 noted by the writer in another connection.* It is based on 

 Phragmicoma, % Ptychanthoides of the Synopsis Hepaticarum, and 

 most of its species would be included in the genera Acrolejeunea, 

 Bracldolcjeunea or Mastigolejeuiica, as these are at present under- 

 stood. The first species listed by Trevisan is P. aulacophonts 

 (Mont.) Trevis. This was originally described by Montagne,f 

 under the name Phragmicoma aulacophora, from specimens col- 

 lected in the Mangareva or Gambier Islands, of Spencer Gulf, 



Aust 



t> 



ing into both Asia and Africa. Ptychocolcus aulacophonts would 

 naturally be selected as the type of the genus. This species, how- 

 ever, is placed by Stephani in Acrolejeunea, and it therefore seems 

 justifiable, in restoring the name Ptychocolcus, to apply it to the 

 genus Acrolejeunea as defined by Spruce and by Schiffner. 



In this restricted sense Ptychocolcus would include between 

 forty and fifty recognized species, all o( which are tropical in their 

 distribution. It attains its best development in southeastern Asia 

 and the islands of the Pacific but is also well represented in Africa. 

 In America five species are at present known, three of which have 

 been reported from the West Indies. Only one species, however, 



polycarpus (Nees) 



Puerto Rico. 



As in the preceding genus, practically all the species of Ptycho- 

 colcus grow on trees or on rotten logs. 



The genus is characterized by an elongated female branch 

 without innovations and by a plicate perianth with smooth keels 

 (plate 7, figure 2), the number varying from four to ten in dif- 

 ferent species. The absence of subfloral innovations will at once 

 distinguish it from Brachiolejeunea, but the two genera agree so 



* Bull. Torrey Club 34 : 543- l 9° s - , , 



t Ann. Sci. Nat. Bot. II. 19 1 259- '843. Voy. au Pole Sud, Lot. 1 : 210. pi. 



19- f- 1. 1845. 



