Evans: HEPATICAE OF PUERTO RICO mal 
to obtuse. suberect divisions, margin as in the bracts; perianth 
much as in D. pellucida, 1.3 mm. long, 0.5 mm. wide: o inflores- 
cence occupying a short branch, not proliferating; bracts mostly 
in from three to six pairs, similar to those of D. pellucida; brac- 
teoles also similar: mature sporophyte not seen. (PLATE 17, 
FIGURES 13-17.) 
On bark of trees. Near Cayey, 1900, Evans (96 in part, 102). 
The writer has examined specimens from the following additional 
localities: near Camp Longview, Florida, Small & Wilson (mixed 
with 2058); various stations on New Providence, Bahama Islands, 
Coker, E. G. Britton ;* Cuba, Ramon de la Sagra, Wright; near Port 
Margot, Hayti, Nash (1765); Troy, Jamaica, Evans (658); Para- 
maribo, Dutch Guiana, Kegel; Petropolis, Brazil, Rudolph, the 
type locality. The portion of the type that was studied is in 
the herbarium of the British Museum and agrees closely with the 
other specimens cited. 
Although the geographical distribution of D. Rudolphiana is 
by no means thoroughly known, it seems to be the dominant 
representative of the genus in the lowlands of tropical America. 
It is often associated with the presence of man and occasionally 
occurs at higher altitudes along roadsides and in plantations. In 
this respect it resembles the common Frullania squarrosa (R., Bl. 
N.) Dumort. It is closely related to D. unidentata but differs 
from it in two important particulars, its autoicous inflorescence 
and the remarkable development of the apical teeth of its lobules. 
€ teeth form a very characteristic feature of the plant, even if 
Poorly developed branches sometimes fail to show them in a 
typical condition, When well developed the apical tooth attains 
alength of about ten cells and is two cells wide for at least half 
its extent. It occupies a position parallel with the axis, and this 
is due, sometimes at least, to a curve at the base. The portion of 
the lobule from which the tooth arises shows an almost straight 
edge, the tooth forming a distinct angle on each side. The base is 
Usually 
the two median cells. The proximal tooth, also, is un- 
8 and distinct but is sometimes strongly inflexed and 
demonstrate. Between the proximal tooth and the 
* Bull. Torrey | Clu 
