180 THE JOURNAL OF BOTANY 
leaves than A. compactum, is by no means so robust as some of the 
forms of the latter species, sje little indeed, if at all larger than 
the type. ‘Thea we mmetri ¢ capsule, curved in the younger state, 
at least doubly greater,” is the only other geass given. Now, 
in one of Aes Bi sranas of No. 188 Drumm. Muse. Amer. in the Kew 
Herbarium (H. serpens var. sanepenter®) the young immature cap- 
sules are similarly curved and asymmetric, and the ripe capsules 
are every whit as large as, indeed slightly larger than, in Kind- 
berg’s specimen ! 
In habit A. compactum closely resembles the more slender forms 
of A. serpens, or even of A. Sprucei, and there is no doubt that it 
have been found more than once growing in company. It is quite 
possible that a caefal search of herbarium specimens of A. Sprucet 
may reveal the presence of the species under notice, which will be 
distinguished by in larger leaves, not at all Remnoaeed to the stem, 
divergent and u sually somewhat homomallous when dry. but, 
although it os. given rise to so much eae and although in 
the field A. compactum, at least in the barren state, is with difficulty 
separated from some of the smaller species of Amblystegium, &c., 
yet under the microscope it is readily recognizable by certain 
salient characters which may be briefly noted. The well-developed 
nerve, broad in proportion to the size of the leaf, and percurrent, 
or at least running well up into the slender acumen; the sharply 
denticulate margin, especially towards base; and the constant 
p recs 
tonemal threads arising from the nerve of many at least of the 
leaves, are the most marked of these characters in ge barren 
stat e nerve, in particular, at once separates 
vi and all t the species of that genus with which ‘. is likely to 
Silaetiches it from Eurhynchium tenellum. much smaller 
pl n A. varium oe and the areolation is entirely different. 
“* broo “ aaa consist of very slender Ease 
eney describes and — the pate cell-wall of the an ae 
cells at mid-leaf as markedly wider than the internal cell-wa 
have, not, however, been able to verify this character on the fee 
examined or on others of the North American plants which I have 
exami 
Th e has a curious tendency to disappear or become 
indistinct shen the middle of the leaf, becoming stronger again in 
the acumen, ough wide and somewhat thick, it is not as a 
rule shin clearly defined, and it varies considerably in width and 
