208 rUOCEEDlNGS (IF Til IC NATIONAL MUSEUM. vol.xxi. 



o\iiiiii)le, weighing' -J."}..")!) kg. There iire- tliree dwarf specimens, Nos. 

 20, 2!>, 12, iiiul 5;}, which, though nearly perfect, must be immature 

 trunks if they beh)ng liere. They dilier too nuicli from each other to 

 constitute a s|)ecilic group, and I liave been obliged to treat them as 

 young, dwarf, or aberrant forms of this species. Nos. 20, 2!», and 42 

 have each a good ternnnal bud, the only such seen in the species. No. 

 53 is very small, only 11 cm. high, weighing only 1.57 kg., short-conical, 

 and very symmetrical. It represents the species in miniature, and is 

 doubtless undeveloped. 



Only one of the si)ecimens of tlie Yale collection from the Dlackhawk 

 region belongs to this s[)ecies, namely. No. 110, which consists of nearly 

 half of a large trunk, showing the much worn outer surface, with deep 

 holes, ■which are often united a short distance within by the decay of 

 the walls so as to produce connnunicating chambers. The opposite side 

 exposes Ui large hollow or trough, consisting of the inner wall of the 

 Avoody zone. It also shows the attachment of the armor and the 

 underlying axis in an exceptional manner. 



CYCADEOIDEA MARSHIANA, new species. 



Trunks very large, profusely branched, the primary branches often 

 bearing secondary ones, the whole individual freipiently consisting of 

 branches, sometimes with a. sort of common base, the branches irregu- 

 lar in size, form, and direction, making shapeless or giotes(iue objects; 

 summits of the branches rounded, bearing small ])olygonal s(;ars witli 

 depressed or ca\i(ous centers separated by deep channels as if from 

 the disappearance of the walls, or filled with the bases of the apical 

 leaves often set in a circular, smooth llattened area and having a small 

 conical i)rotuberance or terminal butl at the center; rock substance 

 hard, heavy, and dark cok)red, general external appearance rough and 

 massive; forms vc'ry variable in size and difiicult to measure, the largest 

 attaining 1>1 cm. in its greatest dimension, the lateral generally greater 

 than the vertical dimensions when standing on the base, the former 

 often 50 to 00 cm., the latter 30 to 40 cm., branches 15 to 30 cm. long, 

 10 to 40 cm. in diameter, and often over a meter in girth; organs of 

 the armor ascending on all the branches; phyllotaxy usually so dis- 

 turbed as not to be traceable, but consisting of at least one series of 

 si)iral rows of scars passing from right to left at an angle of about 75° 

 with the axis of the branch; leaf scars of medium size or small for the 

 size of the trunks, normally subrhombic, but varying from triangular, 

 or with a mere grove to represent the upi)er angle, to nearly rhombic, 

 15 to 30 mm. wide, 7 to 15 mm. high, averaging 12 by 25 mm. for the 

 body of the trunk and 10 by 18 mm. for the branches, usually empty 

 to considerable depth, sometimes tilled with the leaf bases, which 

 either i)resent a smooth concave surface or a rough projecting surface 

 formed in part by rows of pointed elevations consisting of the exposed 

 extremities of the vascular bundles lying on the sides of a central con- 



