196 Evans: HEpPATICAE OF PUERTO RICO 
On bark of trees, more rarely on rotten logs. North slope of 
the Luquillo Mountains, He//er (1233, 4736 p. p.). El Yunque, 
Evans (28, 75, 82, 160). The species is also known, in sterile 
condition, from British Guiana, Greville, the type-locality, from St. 
Vincent (collector not named), and from Martinique and Guade- 
loupe, Duss.* 
C. Chitonia is closely related to C. Peruviana (Lehm. & 
Lindenb.) comb. nov.+, a widely distributed epiphyllous species 
which is also to be expected in Puerto Rico. In fact the two 
species are so closely allied that both Spruce { and Stephani § con- 
sidered them synonymous. The type-specimen of Leyeunea Chi- 
tonia in the Taylor herbarium is sterile aud rather fragmentary but 
is clearly the same as the variable plant described above. It would 
be difficult, however, to gain an accurate idea of the species from 
the type-specimen alone. Odontolejeunea subbifida is a robust and 
sterile form in which the foliar teeth are less pronounced than 
usual. The Puerto Rico specimens show all gradations between 
forms of this. type and those in which the leaves are sharply 
dentate, and in some cases variations of this character are exhibited 
by an individual plant (rFicurE 16). The striking variability in the 
teeth seems to be due, at least in part, to differences in the external 
conditions under which development takes place. When a stem 
or a branch has plenty of room for growth its leaves become large 
and the margin tends to be entire or minutely denticulate ; when a 
branch is crowded or limited in its growth for any other reason the 
leaves are smaller and the margin is more likely to be dentate. 
The production of gemmae is also correlated with an increase in 
the size of the teeth. The variability in the teeth affects not only 
*Cf. Stephani; Urban, Symb. Ant. 3: 277. 1902 : 
+ =_/ungermannia Peruvian na Lehm, & Siadeuhs 3 Lehmann, Pug. Plant. 5: 
18, 1832. Lejeunea Peruviana Lehm. & Lindenb. ; ie, & N. Syn. Hep. 339: 
1845. Lejeunea oat ies Posies Son . Amaz. et And. 15!- 
1884. Odontolejeunea Peruviana Schiffn. ; Engler & ier Nat. Pflanzenfam. 1°: 
« - 1893 
t Hep. Amaz. et And. 152. 1884. 
3 Hedwigia, 29: 70. 1890 et reduced not only Z. Chitonia to synony™Y 
but also Z. foliorum Nees (Syn. H p- 326), and Stephani added Z, adg/utinata Tayl. 
(Lond. Jour. Bot. 5: 389. 1846) Ree L. epitheta Tayl. (/. c. 395). The phate 
mens of the last two species show that while Z. vtehiaiins 4 is a the same a5 
C. Peruviana, L. epitheta is a synonym of Drepanolejeunea inchoata, as since pointed 
out by Stephani himself (Hedwigia, 35: 83. 1896). 
