HOOKER LECTURE, 1922. 233 
hardly distinguishable from Matonia pectinata or M. Foxworthyi has been 
described by Krasser from Lower Cretaceous rocks in Moravia. Specimens, 
which leave much to be desired in the quality of the material, are recorded 
from the Cretaceous of Colorado and from other localities in the United 
States. It would seem that the Matonineæ were not prominent members of 
American Mesozoic floras, but they flourished abundantly in the Jurassic and 
earlier Cretaceous floras of the New World, extending as far north as 
approximately lat, 70? N. in Greenland. 
The problem of the original home of the Dipteris-Matonia stock is not easy 
of solution. When the fossil forms first appear among the records of the 
rocks, certain genera had already reached a vigorous stage of development in 
Europe and North America ; by the Rheetic period they were thoroughly 
established in the Tonkin region, also in Germany and Scania. The oldest 
known genera had fronds of the more completely webbed type and were 
reticulately veined, while such genera as Laccopteris and Matonidium seem 
to have persisted as vigorous types to a later period. There is no good 
reason to suppose that this alliance was more widely represented in Tertiary 
floras than it is at the present day. 
SCHIZÆACEÆ, 
Within this family there is a very wide range in the habit of the fronds as 
represented by the four genera Schiz@a, Aneimia, Lygodium, and Mohria : 
the apical annulus, usually of a single row of cells, and the occurrence of 
the sporangia singly and not in regular groups are constant characters. A 
simple protostele characterises the stem of Lygodium, while other genera 
possess both the solenostelic and dialystelie types of vascular cylinder. In 
several species of Schizea the fronds are slender and filiform like thin blades 
of grass or the cylindrical leaves of a Juncus with clusters of sporangia in 
monangie sori on the reduced lamina at the tips of the fronds: in other 
species the frond resembles a much dissected leaf of Ginkgo, The genus has 
a remarkably wide range in the southern hemisphere, and Schizea pusilla 
extends as far north as Newfoundland (Map €) (Pl. 18). Aneimia, represented 
by several species in South America, oceurs also in Mexico and Texas, the 
Falkland Islands, Abyssinia, South Africa, and India. The fronds are usually 
divided into three branches at the base, the two lateral pinnæ being fertile 
with reduced laminee, and the sterile pinnæ bear segments varying consider- 
ably in shape and in the degree of dissection. Lygodium is characterised by 
a rachis of indefinite growth which behaves as a liane and reaches a length of 
100 ft., giving off dichotomously branched linear pinnæ bearing marginal 
spikes of sporangia. This genus extends from Mexico to Rhodesia, South 
China, Queensland, New Zealand, New Caledonia, and Japan. The genus 
Mohria is represented in South Africa, the Zambesi region, and on Kiliman- 
jaro. An aberrant species from Brazil, one of several xerophytic examples 
