The Jungermannia Section of Liverworts. 335 



bi-trifid, the segments short, setaceous, jointed like conferva; 

 patent and incurved, the fruit terminal upon a short proper 

 branch, the perianth oblong with an open ciliated mouth. It 

 frequents moist and boggy ground in shady places, and also 

 feeds upon the decaying stumps of trees. The foliage of this 

 and that of Jungermannia tricophylla, or the hairy Jungerman- 

 nia, which fruits in June, are so peculiar that they can never 

 be confounded with any other British species, while the differ- 

 ence of their fruiting season sufficiently distinguish them from 

 each other. 



In the next group are included those which have bifid 

 leaves, with unequal conduplicate lobes; and here another sub- 

 division takes place — the first containing those whose lower or 

 smaller segments are plane, and of these the fruit is either 

 unknown or ripens in spring or summer. We therefore pass 

 on to those species which have the lower or smaller segments of 

 the leaves involute, and of these Jungermannia Mackaii, Mr. Mac- 

 hay's Jungermannia, a very distinct and little known species, 

 fruits during winter and spring. It has a creeping and irregu- 

 larly branched stem, bearing leaves unequally two-lobed, the 

 upper lobes rounded, the lower ones minute and involute, the 

 large stipules are rounded obcordate, and the fructification is 

 both lateral and terminal, the capsule globular, of delicate 

 texture, and containing spiral filaments enclosed in trans- 

 parent tubes ; the perianth is obcordate, compressed, gibbous 

 below, with a contracted mouth, which is also toothed. Though 

 rare, this species occurs throughout the limestone districts in 

 the south of Devon, climbing the trunks of trees, and hiding 

 in the fissures of rocks. It has been found in rocks near 

 Torquay, at Lowdore in Cumberland, at Killarney, Ballilicky, 

 near Bantry, by river-side Aber, North Wales, and on Mount 

 Edgecombe. We believe it was first found at Dargle by Mr. 

 Mackay, whose name it bears. 



Jungermannia calyptrifoUa, or the hooded-leaved Junger- 

 mannia, also belongs to this group ; ripens its fruit in October 

 and November, and is not only among the most minute, but 

 likewise amongst the most singular in structure of all the 

 Jungermannise. Unlike the class in general, it grows in very 

 small, scattered, detached tufts ; its very short creeping stem, 

 branched and wearing leaves, so remarkably attenuated at the 

 point, and so like the calyptra of a moss, as to have originated 

 its distinctive appellation. They are unequally two-lobed like 

 the rest of the group, but the larger upper lobe is calyptriform, 

 and the opening at the base is almost covered by the circum- 

 volute lesser lobe, which is obtusely quadrate and incurved. 

 The fruit is lateral, the perianth oblong depressed, with a con- 

 tracted mouth sheltering the base of a short fruit- stalk, which 



