Anacrogynous Jungermanniales. 207 
Fig. 32. Morckia flotowiana. I, Male plant, from above, showing the broad 
midrib covered by toothed scales (male bracts), each of which forms a hood 
over an antheridium, x5. II, Female plant, from above. Six archegonial 
groups are seen. In the four younger groups the archegonia are surrounded 
by the mvolucral leaves (female bracts), the perianth not yet being developed ; 
in the two older groups the perianth is represented as being transparent, to 
show the half-ripe sporogonium within it, x 5. Ill, Female plant, bearingtwo 
ripe sporogonia ; in each case the seta has become elongated, carrying up the 
capsule, which has not yet dehisced, x5. IV and V, Ripe capsules, showing 
different modes of dehiscence, xS. VI, Upper portion of one of the valves of 
a capsule, x 40. 
Blyttiace/e. 
Under this name it is proposed here to designate a family, 
agreeing in part with Spruce’s family “ Leptotheceae,” in which 
Schiffner includes three genera— Pallavicinia, Symphyogyna, and 
Monoclea. The first-named genus should, however, be split into 
the two genera Dlyttia and Morckia ; while Monoclea has been 
removed to the Marchantiales. The recently discovered genus 
Makinoa is probably best placed here, so that our family Blyttiaceae 
includes the four genera Blyttia, Morckia, Symphyogyna , and 
Makinoa. The name Leptotheceae was suggested originally by 
Spruce (60) to include the three genera placed in it by Schiffner 
and also the genus Calohryum, on account of the absence of ring- 
fibres from the cells of the capsule-wall and the incomplete separation 
of the capsule-valves at dehiscence. 
The Blyttiaceae are distinguished from the Aneuraceae chiefly 
by the fact that the sexual organs are born on the upper side of the 
ordinary thallus and not on special short branches. The four 
genera of Blyttiaceae differ in so many respects that it will be 
convenient to describe them separately. 
In Blyttia , the thallus is differentiated into a cylindrical midrib 
and a single-layered wing on either side. In twenty of the thirty 
known species, the whole thallus is attached to the substratum. In 
some cases, e.g., B. Lyellii, the margin of the wing is entire, but in 
several species belonging to this “ Repentes ” section of the genus, 
e.g., B. lougispina, B. xiphioides, the margin bears regular appendages 
which, as shown by Goebel (22, 24), may be regarded as representing 
leaves, since they are formed with great regularity at the growing- 
point, which it is their primary function to protect. In the remaining 
species, forming the section “ Erectae ” or “ Dendroides,” e.g., in 
B. decipiens which was fully investigated by Farmer (16), the thallus 
consists of a creeping cylindrical basal portion, consisting of the 
midrib alone, and an erect distal winged portion which undergoes 
repeated dichotomy, the branches spreading out like a fan—exactly as 
