210 THE LATE DR. NEWELL ARBER : CRITICAL STUDIES 
more recently figured by Kidston (15. p. 83, pl. 8. figs. 2, 3, 3a). The 
major pinnules are large, very variable in shape, and the leaflets resemble 
those of Veuropteris Scheuchzeri, Hoffm., somewhat in habit. They are not 
attached by the whole base, but by a restricted portion, which is, however, 
sufficiently broad sometimes to allow of the origin of some of the lateral 
basal veins directly from the rachis. The lateral nerves are more frequently 
dichotomised than in the minor pinnules, but possess a similar inclination, 
and are also sinuous in their course. 
The continuity between the minor pinnules (N. obliqua of Brongniart) and 
the major (N. acuminata of Zeiller) was first proved in a specimen discovered 
by Weiss, but described by Potonié in 1893 as Neurodontopteris impar. 
This frond shows simple major pinnules on one side and pinnate pinnæ com- 
posed of minor pinnules on the other (fig. 1, p. 209). 
Potonié (22) does not appear to have recognised the identity between the 
minor pinnules of this specimen and the Neuropteris obliqua of Brongniart, 
and even Kidston (15) expresses himself as not quite convinced on this point, 
though he regards it as highly probable. Gothan (11. p. 207), however, has 
more recently referred these specimens to Brongniart’s species, and with 
this conclusion I am also in agreement. [t is thus clear that the terms 
N. acuminata, Zeill., and N. impar, Pot., are mere synonyms of JV. obliqua, 
Brongn. 
Neuropteris obliqua was known to me chiefly by the major pinnules—of 
which there is a good collection from several coalfields in the Sedgwick 
Museum, Cambridge—until a few years ago, when I collected undoubted 
examples of the minor pinnules from the Middle Coal Measures of Bond’s 
Main Colliery in Derbyshire. It is true that I had imagined that one 
already possessed at Cambridge many specimens of these minor pinnules, 
but as soon as I had acquired the Derbyshire specimens I realised 
that I—and, as I believe, others also—had been confusing a quite distinct, 
though similar, plant with the true Neuropteris obliqua. This other type of 
frond, which is much more abundant in Britain than N. obliqua, is here 
redescribed under the name N. callosa, Lesq. 
Remarks on Specimens here figured. 
Excellent illustrations of this species have already been published, so only 
a few selected types are figured here for comparison with the distinct species 
N. callosa, Lesq. 
No. 1430. On PI. 14. fig. 1 is seen, natural size, a typical pinna bearing 
major pinnules of the lanceolate type below and passing above into minor 
pinnules. The larger pinnules have a distinctly sinuate margin. The 
nervation is very clear, except at the base of the pinnules. 
No. 2180. Another specimen from the Ingleton Coal Measures is also 
