ANDKOSTROBUS. Ill 



appears to have been about 1 cm. in breadth, but it is difficult 

 to estimate the dimensions with any accuracy. The surface of 

 the scales is of a brown colour; the longest measures l'5cm. in 

 a direction at right angles to the floral axis; the surface is con- 

 siderably wrinkled and bears obvious traces of having been folded 

 and crushed. Towards one end of the specimen the basal part 

 of a scale is seen in surface view, and on it are clearly preserved 

 what are taken to be the outlines of pollen-sacs (Figs. 3 and 4). 

 These are in the form of small depressed areas radiating from 

 the proximal portion of the scale surface ; each depression is 

 bounded by a straight basal wall, and two slightly diverging 

 lateral walls, with two apical walls inclined to one another at 

 an angle of about 35 ; from the apex there is a slight median 

 ridge passing to the basal wall. In the upper row there are 

 about 14 of these pollen- sac impressions, and below these there 

 are the remains of a lower set of similar structures. Traces of 

 the pollen-sacs occur on some of the other scales, but less clearly 

 preserved. The striking regularity with which these impressions 

 are arranged, is much more marked than in the pollen-sacs of 

 recent cycads. On the lower surface of a staminal leaf of Dioon 

 or EncephaJartos, we find on the removal of the pollen-sacs a 

 fairly distinct reticulate marking, but of much less regularity than 

 in the fossil. The angular outline of the sacs in the present 

 specimens may be due, to some extent, to the mutual pressure 

 of more or less oval structures, such as we have in the pollen- 

 sacs of recent male flowers. 



The tapered free ends of the scales are somewhat similar to 

 the narrowed apices of the staminal leaves of species of Ence- 

 phalartos ; e.g. the male flower of E. Altensteinii, Lehm , E. 

 pitngens, Lehm., etc. Cf. Androstrobus Balduini, Sap., pi. cxv. 

 figs. 2a and 2b. 1 Ecclesbourne. Rufford Coll. 



V. 2810. PI. IX. Fig. 1. 



7 cm. in length. This specimen shows several fairly well- 

 preserved scales somewhat closely set on a central axis which 

 is narrower than that in V. 2701. Each staminal leaf presents 

 a triangular outline, with a more or less distinct median ridge 



1 Loc. cit. 



