210 - Evans: Notes ON GENUS HERBERTA 
Most of the earlier writers not only failed to distinguish 
H. Hutchinsiae from H. adunca but considered the combined 
species a mere variety or form of the Jamaican H. juniperina 
(Sw.) Trevis. (Jungermannia juniperina Sw.). Hooker was appar- 
ently the first to advance this idea. In the text accompany- 
ing pl. 4 of his British Jungermanniae he recognized J. juniperina 
as a member of the British flora and included J. adunca under the 
variety ‘‘B,” to which he did not even give a definite name. 
‘“‘After a most careful examination of Mr. Dickson’s J. adunca, 
compared with others of J. juniperina, which I have received 
from Dr. Swartz,” he adds in a critical note, ‘“‘I am unable to find 
any characters which can induce me to keep them separate.” He 
then calls attention to the larger size of the Jamaican plant and 
to the greater readiness with which it regains its original appear- 
ance when immersed in water but clearly regards these features 
of but little moment. Weber* protested against Hooker’s treat- 
ment of J. adunca and maintained it as a valid species, in which 
he was followed by both S. F. Gray and Dumortier. The majority 
of contemporaneous writers, however, followed the example of 
Hooker, and the Synopsis Hepaticarum, in 1845, went so far as 
to cite Scottish specimens under Sendinera juniperina 8, without 
even mentioning J.adunca asasynonym. When Gottsche, nearly 
twenty years later, distinguished between his a Dicksoniana 
and 8 Hutchinsiae, he pointed out in addition the most marked 
differences between H. adunca and H. juniperina; and, since this 
time, both species have been almost universally recognized. 
Among the characters of H. adunca which Gottsche emphasized 
was the lack of teeth on the leaves and underleaves. He pointed 
out the fact that young leaves sometimes showed five to eight 
primordial papillae at the base, these structures representing the 
rudiments of teeth, but of actual teeth he found no development. 
Although this description will apply to the vast majority of leaves, 
it will not apply to all. An occasional leaf will show one or perhaps 
two teeth in the basal region. Such a tooth usually consists of a 
single cell, serving as a stalk for a papilla, but it sometimes attains 
a length of several cells and becomes more lobe-like in appearance. 
The occurrence of these teeth, in view of their infrequency and 
* Hist. Musc. Hepat. Prodr. 54. 1815. 
