440 MESOZOIC FLORAS OF UNITED STATES. 



thin, 2 cm. to 4 cm.; liber and cambium obscure; wood}' axis divided 

 into several rings, sometimes consisting of a loose, open structure sep- 

 arated by thin, firm plates, the inner face next the medulla definitely 

 marked by the remains of vessels and medullary ra^^s; medulla large, 

 marked on the external surface by thin longitudinal ridges or lamellae 

 varying from 1 cm. to 3 cm. in length, the ends overlapping adjacent 

 ones (Cycadeomyelon saporta), internal parts coarse and porous or 

 somewhat chambered. 



This species resembles Cycadeoidea McGeeana in the general form 

 of the trunks, but the external organs are very different, the most striking 

 distinction being the very thick walls. It now embraces 27 specimens, 

 12 of which have come to light since it was originally described in 1897. 

 The two smaller specimens in the museum of the Maryland Academy 

 of Sciences have been somewhat doubtfully referred to this species. 

 They are fragments and show so few characters that their specific relations 

 are obscure. 



These are not figured and may therefore be briefly described here. 

 The first of these, called the Maryland Academy cycad No. 3, is the third 

 in size of the four specimens in the museum of the Maryland Academy 

 of Sciences and is a fragment from one side of a small trunk. It includes 

 nearly or quite half of tlie external surface, unless it should represent the 

 thin side or edge of an elliptical trunk — which can not be certainly ascer- 

 tained, but seems probable, the specimen including one of the narrow 

 sides and part of one of the broad ones. It is of a dark reddish-brown 

 color, lighter within, rather soft and porous, and of low specific gravity. 

 It is 21 cm. in length (height) and 14 cm. in diameter, and is 6 cm. to 

 9 cm. in radial thickness. 



The other, called the Maryland Academy cycad No. 4, is the vsmallest 

 of the four specimens in the museum of the Maryland Academy. It is 

 a mere cap, broken by a nearly horizontal cleavage from the top of a 

 large trunk, and this is in turn broken along a vertical plane a little to 

 one side of the center. There is a distinct terminal bud, and this is 

 wholly included in the specimen. The upper surface is badly worn and 

 shows nothing but a warty, uneven structure, but the boss representing 

 the terminal bud is set in a slight depression. The bud is decayed at 

 the base so as to be visible from below. The broken surfaces all show 



