656 PROFESSOR A. C. SEWARD ON 



and differ considerably in shape. I am, however, unable to detect any satisfactory 

 distinguishing features which justify the specific separation of the several specimens. 

 A considerable range in form and size, in the extent and distinctness of the midrib, and 

 in the contour of the apex is characteristic of the genus ; moreover, an examination of 

 a large number of leaflets shows that such distinct forms as those shown in figs. 1 and 

 3, PI. I., and photo. 5, PI. VI., are connected by intermediate types. The portion of a 

 leaf, 8 cm. long, represented in photo. 5, PI. VI., must have reached a length of at least 

 1 1 cm. The midrib extends almost to the apex, and the lateral veins form narrow and 

 long areolae as they bend steeply upwards and outwards to the edge of the lamina 

 (text-fig. 1). This larger form of leaflet bears a close resemblance to some specimens 

 from the Inferior Oolite of Yorkshire described as S. Phillipsi var. major* Photo. 4, 

 PI. VI. , shows an almost complete leaflet in which the midrib is particularly distinct 

 and the characteristic asymmetrical form of the lamina is clearly shown. This specimen 



Text-Fig. 1. — Sagenopteris Phillipsi (Brongn.). Reticulum of secondary veins, with a portion of 

 the midrib on the left. The long sides of the areolae are approximately - 6 mm. apart. 

 (Gunn collection.) 



appears to be indistinguishable from S. Nilssonicma ( = S. rhoifolia) as figured by 

 HALLE.t The best example in the collection is that shown, rather less than natural 

 size, in photo. 3, PI. VI. A small piece of axis on the left of the leaflets may be a 

 portion of the common petiole. Fig. 1, PI. I., shows a slightly larger leaflet in which 

 the apex is somewhat sharper. The linear leaflet, 5*5 cm. long, represented in fig. 3 

 agrees closely with some of the Yorkshire specimens referred to this species ; the 

 secondary veins are obscure, but the midrib is distinct. This narrower form agrees 

 more nearly with S. undulata Nath. than with the other Rhsetic species S. Nilssoniana. 

 The preservation of the specimen shown in fig. 4, though far from good, is sufficiently 

 clear to enable one to refer it to Sagenopteris. The leaflets are to some extent 

 intermediate in shape between the longer forms shown in fig. 3 and the shorter and 

 broader examples shown in fig. 1 and in photo. 3, PI. VI. The apical portion represented 

 in fig. 2 illustrates a lanceolate termination in contrast to the broader tips of many 

 specimens. The small cuneate leaflet seen in photo. 19, s, PL VII., is identical with the 

 type described by some authors as a separate species, S. cuneata ; it is almost certainly 

 a small form of S. Phillipsi. 



* Seward (00), fig. 2G, p. 160 ; (00 2 ), pi. iii. fig. 8. t Halle (10), pi. H. figs. 19, 20, etc. 



