(^E BLUT A, e EIER. Y 
h k M T PS 
D -n e taxe Om. t m 
M Eme ais See Ty 
74 Rhodora [APRIL 
fortunately the International Rules of Botanical Nomenclature make 
no definite provisions for cases of this kind, although they advise that 
the use of homonyms be avoided in the future (see Recommendation 
V, b., on page 39). Among the amendments proposed by certain 
American nomenclature committees in 1909, there was one which 
provided for the absolute rejection of all generic names which were 
homonyms. It was hoped that this amendment would be voted 
upon at the International Congress which met at Brussels in 1910, 
but unfortunately no such action was taken. The question of homo- 
nyms, therefore, remains unchanged, and there is no international 
rule of nomenclature which would prevent the use of the name Dip- 
lophyllum of Dumortier. In addition to Diplophyllum gymnostomo- 
philum, the New England flora contains the following members of the 
genus: D. albicans (L.) Dumort., D. apiculatum (Evans) Steph.,? and 
D. taxifolium (Wahl.) Dumort. These three species are given under 
Diplophylleia in the writer’s “Revised List of New England Hepati- 
cae." ? 
Since D. gymnostomophilium is fully described and figured by Kaa- 
laas and, more recently, by Nicholson,‘ only a few of its more important 
peculiarities will be discussed in the present paper. The plants are 
more or less tinged with yellowish brown and usually grow mixed with 
mosses. The stems are about 2 cm. long and are rarely branched. 
The ventral lobes of the leaves spread widely from the stem, often at 
more than a right angle and attain a size of about 1 X 0.6 mm. when 
well developed. They are oblong in form and more or less falcate, 
the curved lateral margins tending to be parallel. The apex is nor- 
mally rounded, although the production of gemmae sometimes makes 
it more or less pointed. The dorsal lobes spread obliquely, at an angle 
of forty-five to sixty degrees; they are ovate in form and measure 
about 0.6 X 0.35 mm. The apex is commonly pointed and is some- 
times apiculate. The margins of both lobes are entire throughout, 
and the sharp keel connecting them is usually distinetly incurved. In 
the ventral lobe the marginal cells measure about 14 u in diameter, 
while the median cells measure about 22 X 16 yu. The latter tend to 
be arranged in longitudinal rows, but this arrangement is not always 
1 See Bull. Torrey Club 36: 61. 1909. 
? Sp. Hepat. 4: 110. 1910. 
3 Reopora 16: 23. 1913. 
4 Jour. Bot. 51: 158, pl. 526, f. 1-6. 1913. 
- 
— np" Sn. 
