186 WILLIAMSONIA. 



difference in form and manner of attachment of the apical, median, 

 and basal pinnae. The longer central pinnse have a length of 

 7'5 cm., those at the base are about 3-5 cm. long, while the apical 

 pinnao are longer, more linear, and less pointed. 



V. 2723. A fine frond similar to V. 2722. Beckkt Coll 



V. 3507. Good fronds with broad pinnse showing clearly 

 preserved venation ; the pinnae are oblique to the matrix, and 

 therefore appear narrower than they really are, and at first sight 

 they suggest an Otozamites rather than a Zamites type. Purchased. 



V. 3942. A frond 53 cm. long. This specimen is preserved in 

 sandstone, and does not show the details so clearly as many of 

 the other examples of this species, but it affords a good illustration 

 of the danger of relying too much on the published figures of 

 fossil fronds. If this frond were drawn as it appears on the 

 sandstone, the pinnae would seem to have broad basal portions 

 rapidly tapering towards the apex ; in reality the breadth of the 

 pinnae is fairly uniform to within a short distance of the apex, but 

 owing to the oblique position of the pinnse in the sandstone matrix, 

 a considerable portion of the lower edges is hidden and would not 

 be seen in a drawing or photograph. 



38.760. A splendid frond 45 cm. in length, including the 

 petiole, which measures 4'5 cm., widening towards the base. 

 This frond is unusually complete, showing both the apical and 

 basal pinnae. The tips of the pinnae are seen to vary considerably : 

 in some the upper and lower margins bend gradually downwards 

 and upwards respectively towards the symmetrically placed 

 acuminate apex ; in some the apex points upwards ; and in others 

 the lower margin of the pinnae is almost straight, while the 

 upper margin bends strongly downwards and gives the apex the 

 appearance of pointing slightly downwards. 



Scarborough. 



38.761. Good examples of fronds associated with a flower 

 of oval form and closely invested by linear bracts, many of which 

 show the obliquely set ramenta, which are frequently met with. 

 on the bracts of Williamsonia gig as. 



