12 11 u I'd *Sy)(T/r-s o/ Oycdd&yidcQ. fi'om Mo/rylcLnd. 



tissue without and within, its inner wall strongly marked with longi 

 tudinal grooves ; medulla distinct and homogeneous, light and porous. 



This species is represented only by a single specimen, No. 1472 of the 

 Woman's College. It approaches C. Marylandica in some respects, but 

 differs in the larger leaf scars, thinner walls, thicker armor, and the great 

 paucity of reproductive organs. It is to be regretted that Professor Fon 

 taine did not name the original species with which Mr. Tyson's name 

 will always be so intimately connected in his honor instead of the genus, 

 ' which must fall before the laws of nomenclature. I have endeavored in 

 the above name to supply the defect in some small degree. 



Cycadeoidea McGeeana n. sp. 



Trunks low and flat, with ample diameter, sometimes three times as 

 thick as high, yellowish, brown, or nearly black, more or less porous and 

 spongy, and of low specific gravity ; leaves and spadices set nearly at right 

 angles to the axis ; leaf scars arranged somewhat definitely in quincunx 

 order and disposed in spiral rows around the trunk, small and uniform in 

 shape, subrhombic with the vertical angles obtuse, the lateral ones acute, 

 narrow-elongate, 6 to 10 millimeters in vertical by 16 to 20 millimeters in 

 lateral dimensions, averaging 8 by 20 millimeters, usually empty by the 

 disappearance of the leaf bases, at least to a considerable depth ; ramen- 

 tum walls thin, often less than one millimeter, with or without evident 

 commissure, and with occasional punctations ; axes of inflorescence few 

 and scattering, sometimes projecting and filled with the substance of the 

 spadix, sometimes cavitous from the decay of the essential organs, sur 

 rounded by obtusely triangular or somewhat crescent-shaped bract scars ; 

 armor 4 to 5 centimeters thick ; liber and cambium sometimes distin 

 guishable; woody zone usually divided into two or three rings; medulla 

 large, porous. 



A very distinct species of low and squat trunks, some of them having 

 almost the form of a car wheel, only a very small part of which can be 

 due to vertical compression. The external organs, however, closely re 

 semble those of C. Tysonicma. It embraces seven specimens, all belong 

 ing to the Woman's College, as follows: Nos. 1471, 1659 and 1659, which 

 belong together, 3055, 3068, 3323, 3325, and 3349. The most complete 

 specimen is No. 1471, which is taken as the type and which has been cut 

 through vertically and the surfaces polished. The specimen consisting 

 of the two complementary fragments 1659 and 1659 is also very interest 

 ing, though representing only about two-thirds of the whole trunk. The 

 other specimens are all fragments. 



I have named the species for Mr. W J McGee, by whom the Potomac 

 formation was named and whose extensive studies in that formation are 

 well known. As stated above, it was largely through his efforts that in 

 terest in the cycads of the formation was revived, and he it was who 

 caused the photographs to be taken that were used to illustrate Professor 

 Fontaine's monograph of the flora. 



