308 G. R. Wieland — American Fossil Cycads. 



In figure 5 is shown a longitudinal section through the pali- 

 sade parenchyma and bundle connection, with the hypodermis. 

 This section displays clearly the usual dichotomous cycadean 

 venation, as well as the mode of bundle increase. The pinnae 

 are of linear-lanceolate form, and without a distinct midrib. 



A comparison of these structures with those of Zamia 

 integrifolia shows a striking resemblance in all essential char- 

 acters, — a resemblance that is even more marked than is that 

 between the pinnge of Zamia and of some o£ the other existing 

 genera of the Zamiacece (Zamica). 



The character of the ram en turn, surrounding these leaves 

 remains to be briefly mentioned. It consists of thin scales, or 

 hairlike forms, composed of stringy elements, and strongly 

 resembles the ramental cells figured by Carruthers 3 and Seward 15 

 in their respective descriptions of Bennettites Gibsonianus and 

 Cycadeoidea gigantea. A transverse section of the ramentum 

 is shown in figure 6. The flat sides of these scales quite uni- 

 formly face the leaves, though as such a large portion of the 

 summit is occupied by a mat of relatively the same character, 

 it is probable that much of this hairy and scaly material is 

 borne on the trunk in the space intervening between the 

 petioles of the young leaves. 



Yale Museum, New Haven, Conn., March 20, 1899. 



EXPLANATION OP PLATE VII. 



Figure 1. — Diagram of a hypothetical leaf, with a reduced number of pinnules, 

 showing the position of the sections represented in figures 2 and 3. 

 0, 0', are in the plane of the transverse section, figure 2, and also 

 approximately mark the base of the longitudinal section, figure 3. 



Figure 2.— Cycadeoidea ingens, Ward (type); transverse section through upper 

 portion of young leaf, x 4. For relative position, see figure 1. 



a, upper side of an inner pinnule cut near the summit; b, fibro- 

 vascular bundle ; c, pinnule cut near the base ; d, axis of growth of 

 rachis. The arrows indicate approximately the base line 0, 0', 

 figure 3. 



Figure 3. — The same specimen ; longitudinal section through summit of young 

 leaf, x 4. For relative position, see figure 1. 



a, summit of a pinnule near apex of leaf ; b, upper side of pinnule; 

 c, base line of section indicated in figure 1, 0, 0'. 



Figure 4. — The same specimen; transverse section through a single pinnule, 

 showing a fibro-vascular bundle, x 60. 



a, upper side of leaf ; b, hypodermis ; c, sclerenchyma connection 

 of hypodermis with fibro-vascular bundle ; d, palisade parenchyma ; 

 e, xylem; /, phloem; g, spongy parenchyma; h, epidermis of under 

 side of leaf. 



Figure 5.— The same specimen; longitudinal section through a pinnule just 

 beneath the hypodermis cutting the palisade parenchyma, x 35. 

 a, forking vein ; 6, palisade parenchyma. 



Figure 6.— The same specimen; transverse section through the rameotum sur- 

 rounding the young leaves, x 60. 



