572 PTERIDOSPERMS, ETC. [CH. 



of Yorkshire and described in 1888 ^ affords a striking example 

 of the large size attained by what was probably a frond of 

 Neuropteris. The piece of main rachis reached a length of 

 over 120 cm. and bore five pairs of Cyclopteris pinnules, some 

 of which were 7 cm. long and 5 cm. broad. The complete 

 frond must have reached a length of at least 4 metres. Fig. 370 

 shows some typical Cyclopteroid leaflets on the petiole of a 

 Neuropteris frond. 



Linopteris. 



The Upper Palaeozoic fronds included in this genus are 

 more familiar as species of Dictyopteris. Potoni^'' has, however, 

 pointed out that the creation of this name by Lamouroux in 

 1809 for a genus of Brown Algae which is still retained, makes 

 it advisable to fall back upon the designation Linopteris. 

 Gutbier ^ proposed the genus Dictyopteris in 1835: Linopteris 

 was first used by Presl* in 1838. The fronds so named are 

 identical with species of Neuropteris except in the anastomosis 

 of the secondary veins ; Linopteris bears to Neuropteris the 

 same relation as Lonchopteris bears to Alethopteris. As in 

 Neuropteris, Cyclopteroid pinnules occur on the petioles of Lino- 

 pteris, but the veins form a fine reticulum. Grand'Eury^ records 

 the association of Linopteris Brongniarti with seeds belonging 

 to the genus Hexagonocarpon, a fact which points to the 

 Pteridosperm nature of the foliage. 



Some fertile pinnules of Linopteris Schutzei (Roemer) are 

 described by Zeiller" from Autun as bearing on the under 

 surface of the lamina two rows of long and pointed sporangia, 

 probably united in groups. The presumption is that these are 

 microsporangia. 



Fig. 374 is a reproduction of a careful drawing, originally 

 published by Zeiller', of a pinnule of the type-specimen of 

 Gutbier's species Linopteris neuropteroides. This species differs 

 from Linopteris obliqua, instituted by Bunbury * for specimens 



1 Seward (88). '' Potoni6 (99) p. 153 (note). 3 Gutbier (35). 



* Presl, in Sternberg (38) A. » Grand'Eury (04). 



« Zeiller (90) PI. xi. fig. 9. 



7 Zeiller (99) p. 46. s Bunbury (47) A. p. 427. 



