32 DAVALLIOID FERNS [CH. 



The leaves are variously pinnate, with fan-shaped or trapeziform pinnae 

 and segments. For the most part the venation in Lindsaya is dichotomous 

 and free: but certain species, grouped as '^Synaphlebmm by J. Smith, have 

 anastomosing veins, though with the same habit and texture as the rest. In 

 this respect they may be held as more advanced. Others have the blade 

 condensed to a simple expanse, though with the veins free (Z. \^Sc]iizolomd\ 

 reniformis Dry., and L. \_ScJii:;oloi}ia\ sagittata Dry.). 



Fig. 6oi. A single pinna of Lindsaya lancea (L.) Bedd., 

 showing the soil fused laterally to form an almost 

 continuous intra-marginal series, or coenosorus. (X4.) 



The sori of Lindsaya are fused in varying degree in the several species 

 into coenosori, which may extend along the margin of a large pinnule with 

 or without interruptions (Fig. 601). The coenosorus appears intra-marginal, 



W :■,■■■ • -. -J 



Fig. 602. A small part of the marginal region of a pinna of Lindsaya lancea (L.) Bedd., showing an 

 incomplete lateral fusion of the sori. To the left is an almost isolated sorus of the Saccolotna type: 

 to the right more complete fusion is seen, while vascular commissures connect the receptacles. 

 (From a drawing by Dr J. McL. Thompson.) ( x 70.) 



with a continuous flap of a membranous lower indusium, while the upper 

 appears as an extension of the blade. Below the receptacle the veins are 

 connected by a vascular commissure, which is also liable to interruptions 

 (Fig. 602). The development of the sorus has been traced in L. linearis Sw, 



