FOSSIL CYCADEAN TRUNKS FROM WYOMING 27 1 



thick, sometimes in 2 rings with radiate structure ; medulla 3-6cm in 

 diameter, fine-grained and homogeneous. 



This species is one of the most common in the Jurassic of Wyoming 

 and is typical of the smaller branching forms. It embraces Nos. 500.5, 

 500.23, 500.30, 500.36, 500.38, 500.41, 500.49, 500.70, 500.77, 

 500.78, 500.80, and 500.82. Nos. 500.49 and 500.77 fit together, 

 and No. 500.41 evidently belongs to the same trunk. A small piece 

 has become detached from No. 500.49. Nos. 500.78 and 500.82 also 

 fit together, and No. 500.70 seems to form a cap to this small trunk, 

 but a portion is lost between them. The rest are all single. Nos. 

 500.5 and 500.23 are practically complete trunks. Nos. 500.36 and 

 500.38 are parts of two of the largest trunks of tlie species, and No. 

 500.30 is over half of another nearly as large. They are all very 

 handsome specimens, presenting the regular mottled striped or spotted 

 appearance due to contrast between the dark leaf bases and the light 

 colored walls. No. 500.23 is nearly unbranched and is anomalous in 

 several respects. It may represent a different species, but cannot be 

 identified with any other specific group. 



The weights of the specimens is as follows : 

 No. 500.5, 2,41 kilograms. 



" 500.23, 1.05 " 



♦' 500.30, 2.30 " 



" 500.36, 3.43 



" 500.38, 3-32 " 



" 500.41, 0.37 '' 



'' 500.49, 1.84 " 



" 500.70, 0.56 " 



" 500.77, 1. 14 " 



" 500.78, 0.79 " 



" 500,80, 0.79 " 



" 500,82, 0.62 *' 



CYCADELLA NODOSA n. sp. 



Trunks small (8-izjcm high, io-20cm in diameter), ellipsoidal or 

 conical, somewhat laterally compressed or otherwise distorted, covered 

 with small secondary axes forming prominences or protuberances and 

 giving the specimens a kotty or gnarly appearance ; rock hard, light 

 ash colored or brown on weathered surfaces, black within, of medium 

 specific gravity ; organs of the armor generally horizontal ; leaf scars 

 subrhombic, i5-2omm wide, 5-iomm high; leaf bases punctate with 

 small white tubes; walls i-3mm thick, firm, light colored, striate, 

 sometimes with a median groove or line; reproductive organs few, ob- 

 scure, simulating the secondary axes, surrounded by large subrhombic 



