496 PTERIDOSPERMS, ETC. [CH. 



inclined towards one another so that they form with the axis of the pinna 

 a wide-open V instead of lying in one plane (fig. 333, C). From a median 

 rib are given off numerous anastomosing branches (fig. 333, B). 



This characteristic Wealden species is recorded from England, 

 Germany, France, Belgium, Austria, Russia, Bornholm, North 

 America, and Japan. It is by no means certain that Weichselia 

 Mantelli is a true fern : no satisfactory evidence of fructification 

 has been adduced. 



The broad and strong rachis is comparable with that of 

 a Cycadean leaf and the thick lamina suggests a plant of 

 xerophilous habit. I have retained the specific name Mantelli 

 on the ground of long established usage instead of following 

 Fontaine in his adherence to strict priority. 



Glossopteris. 



The name Glossopteris was proposed by Brongniart in 1822^ 

 for an imperfect leaf-impression which he called Filicites 

 (Glossopteris) dubius, but the specimen so named has since 

 been identified as part of a sporophyll of a Lepidostrobus. The 

 author of the genus afterwards published ^ a diagnosis, based 

 on well-preserved leaves from Permo-Carboniferous rocks in 

 Australia and India, of the type-species Glossopteris Browniana, 

 the Indian examples being distinguished as G. Browniana var., 

 indica while the Australian form was named G. Browniana 

 var. australasica. Schimper^ afterwards raised the Indian 

 fossils to specific rank as G. indica though some authors* have 

 continued to consider the two forms as insufficiently distinct to 

 be regarded as different species. 



The genus Glossopteris may be defined as follows : 



Leaves simple, varying considerably in size, shape, and venation 

 characters, but almost without exception characterised by repeatedly 

 anastomosing lateral veins. The leaves are of two kinds : (i) foliage 

 leaves ; apparently always sterile, usually spathulate, with an obtuse apex, 

 a well-marked midrib which may persist to the apex or die out in the 

 upper half of the lamina, characterised by its slight prominence and 

 comparatively great breadth especially in the basal part of the frond. In 



1 Brongniart (22) A. PI. ii. fig. 4. = Brongniart (282) A. Pis. lxii. lxiii. 

 •» Schimper (69) A. p. 645. * Seward (97=) A. p. 317. 



