222 I'liOVEEDINGS OF TUE NATIONAL MUSEUM. 



lijiving: a maxiiuum lenj^ftli of 85 (;in. Its diaiiieters are, resi)ectively, 

 G2 cm. and R) cm., mhX it lias a girtli of 170 cm. But like all other 

 specimens of this species it diminishes in size toward each end and is 

 somewhat barrel-shaped.* Nos. 10.'5 and 117 represent the lower i)art of 

 two other hirji^e trunks, and the summit is re[)resented oidy in No. 100. 

 No. 94 comes next in point of interest in al'iordinj;' most of our knowl- 

 edge of the internal structure of the species, including the markings 

 on the medulla. No. 12.'} is also instructive from this ])oint of view. 

 The rest are fragments, but all add to the complete conception of the 

 species. 



The form of the leaf scars is imitated very closely by two other 

 si)ecies, one of wliich, (J./onnoso, is represented by only one specimen, 

 No. 81). The other is (J. still locUi, and this is made very clear by the 

 new nuiterial added by the specimens last sent from the Blackhawk 

 region by Mr. Wells, (ispi^cially No. 105. In both these cases, however, 

 the scars are much smaller, and this is particularly the case with C. 

 stilltcelli. 



CYCADEOIDEA FORMOSA, new species. 



Trunks of moderate size, short conical, unbranched, dark brown, 

 nearly black within, of average specilic gravity, about 25 cm. high, 

 nearly 30 cm. in diameter and having a girth of somewhat less than a 

 nu'tia"; organs of the armor, even the lowest, somewhat ascending 

 with a uniform angle; leaf scars arranged in two scries of spiral rows, 

 those of both series making an angle with the axis of about 50°; scars 

 large for the size of the trunk, peculiar in shape, the lateral angles 

 very sharp, the vertical ones very obtuse and rounded, the bounding 

 sides usually curving downward and upward on the right and left 

 causing the scars to be drawn out laterally corresponding to wings of 

 the petioles, lower side more pronounced than the upper in such a man- 

 ner that a linefoining the lateral angles divides the scar into unequal 

 areas, varying to sim[)ly gibbous by the absence of the above described 

 curves; distance between lateral angles 25 to 30 mm., that between 

 highest and lowest points 10 to 20 mm. ; leaf bases always present, usu- 

 ally projecting somewhat, sometimes nearly 1 cm., outlines delinite, 

 conforming to shape of sc^ars, exi)osed ends i)resenting surfaces that are 

 exactly s([uare (»r tangential to the trunk, never convex nor concave, 

 smooth but not polished, covered by a diaphragm representing a natu- 

 ral plane of disarticulation, this layer, however, sometimes removed, in 

 which case small projecting points are irregularly scattered over the 

 surface of the leaf base; outer row of leaf bundles very close to the mar- 

 gin, faintly visible at the ends, more clearly as striae on the eroded 

 sides of projecting leaf bases; ranientum walls thin, 1 to 3 nun., thicken- 

 ing at the angles, sunk below the petioles and usually separated from 

 them by a crack, dull colored, loose in structure and somewhat pitted, 

 having the ai)i)earance of (;racks tilled with mud or extraneous matter; 

 reproductive organs numerous and well marked, occurring at all points. 



