FOSSIL CYCADEAN TRUNKS FROM WYOMING 283 



Carbon County in which, the locality for all the specimens is located. 

 It constitutes an almost complete trunk, but came in two nearly equal 

 pieces, the fracture passing through the narrowest dimension, through 

 the center of the apex, down the back and lower side and emerging at 

 the center of the basal concavity along a nearly even plane. Unfortu- 

 nately the interior thus exposed shows scarcely any structure. 



CYCADELLA KNIGHTII n. sp. 

 PI. XXI. 



Trunks very large (30-4ocm high, 19x28cm in diameter), sub- 

 ellipsoidal, somewhat laterally compressed, unbranched, depressed at 

 the summit; axis eccentric; rock hard, somewhat mineralized, dark 

 colored or nearly black, of high specific gravity ; organs of the armor 

 horizontal ; rows of scars from left to right forming an angle of 45° 

 with the axis, those from right to left of 70° ; leaf scars subrhombic 

 or subelliptical, i8-2omm wide, 8-i2mm high; leaf bases hard, punc- 

 tate; walls 3-5mm thick, hard, sti-iate, with or without a median 

 groove; reproductive organs few, poorly developed, flush with the 

 surface or slightly raised, elliptical in cross-section, 2 x3cm in diame- 

 ter, surrounded by large subrhombic involucral bract scars passing into 

 leaf scars, the central portion solid and showing the scars of the floral 

 organs ; armor 4-6cm thick, obscurely attached to the axis ; woody 

 zone 3-4cm thick, undifferentiated; medulla 6x locm in diameter, dif- 

 ficult to distinguish from the woody zone, hard, and black with flinty 

 or crystalline areas. 



The next largest specimen in the collection and probably the finest 

 from the standpoint of symmetry and general appearance is No. 500.- 

 65. It came in two pieces of unequal size caused by a transverse frac- 

 ture below the middle. The larger piece weighs 15.48 and the smaller 

 9.8 kilograms, making the total weight 25.28 kilograms. There was 

 one other specimen, viz.. No. 500.33, which so closely resembles this 

 that it is impossible to separate it. It consists of considerably over 

 half of the lower portion of a somewhat smaller trunk, having the base 

 perfect and a nearly horizontal transverse fracture across the trunk 

 above. This weighs 8.87 kilograms. 



I take great pleasure in dedicating this fine species of Cycadella, to 

 Prof. Wilbur C. Knight, State Geologist of Wyoming, through whose 

 enterprise the collection was made and w^ho has so generously placed 

 it in my hands for elaboration. 



PI. XXI represents the best preserved side of No. =^00.65. 



