214 . THE LATE DR. NEWELL ARBER: CRITICAL STUDIES 
No. 1170. Some pinnules, larger still, are shown magnified three times 
in fig. 12. Some of these measure 12 mm. in length. The characteristic 
nervation is clearly seen 
No. 2381. The terminal region of the pinna in which some of the pinnules 
reach a length of 15 mm. is shown enlarged twice in fig. 13. The tip of the 
terminal pinnule is hidden in the rock. 
No. 2632. A fragment of an apical portion of a pinna in which the 
pinnules are very small, but the nerves clearly seen, is shown in fig. 14, 
enlarged three times. 
No. 1916. In fig. 15 an enlarged photograph of a specimen from the 
Kent coalfield, which I figured in 1909, is given. The pinnules are here 
elongately oval, nearly 2 em. long, and overlap one another. 
Diagnosis of Neuropteris callosa, Lesq. 
Frond large, tri- or ?quadripinnate. Penultimate pinnæ broad, often but 
not always with a broad axis; ultimate pinnæ lanceolate, axis very slender. 
Pinnules typically Neuropteroid, inserted. by a very small part of the base, 
oval or elongately oval, varying much in size from about 4 mm. up to 20 mm. 
or more in length, entire, broadly rounded at the apex, markedly cordate, 
almost eared at the base, closely set on the axis, and frequently overlapping 
one another. Pinnules markedly caducous. Nervation clearly marked, but 
nerves fine, all nearly equally strong and equally spaced, lateral nerves all 
arising from the median nerve, not crowded, somewhat arched, flexuous in 
their course, dichotomising once to three times. Lamina between the veins 
frequently punctate. Terminal pinnule rather small, elongately lanceolate 
or oval-lanceolate. 
Distribution. 
The distribution of Neuropteris callosa, Lesq., in this country, so far as it is 
known to me, is :— 
Transition Coal Measures. 
Kent: Several borings at Waldershare, etc. 
Middle Coal Measures. 
Kent: Many borings at Goodnestone, etc. 
Pembrokeshire: Rickets Head, near Newgate, etc. 
Wyre Forest: Kinlet, Alton Boring, No. 1. 
Titterstone Clee Hills: South Coal. 
Yorkshire (Derbyshire): Below Top Hard Coal, Shipley. 
Yorkshire : Monkton Main Colliery. 
? Ingleton : Ingleton Colliery. 
