Maryland Geological Survey 417 



those of the same age are often quite variable in size. The bordered 

 pits were not observed except in a single row and are not especially close 

 together. In the radial section the ray pores can occasionally be made 

 out. They are small and circular and not more than two were observed 

 in the width of a wood cell. 



There is great variability in the rays, which may consist of a single 

 or but two cells, or a ray may be made up of twenty or thirty cells in 

 a single row, or a high ray may be double at either end or merely in 

 the middle, or small rays only 4 or 5 cells high may be double throughout. 



Occurrence. — Patuxent Formation. Clifton (Baltimore), Maj-y- 

 land; JSFear Montello, District of Columbia, ISTeabsco Creek, Virginia. 



Collections. — U. S. National Museum, Johns Hopkins University. 



CuPRESSiNOXYLON McGeei Ejiowlton 

 Plate LXIX, Figs. 1-6 



Gupressinoxylon McGeei Knowlton, 1889, Bull. U. S. Geol. Survey, No. 56, 

 p. 46, pi. ii, fig. 5; pi. Hi, figs. 1-5. 



Description. — " Annual ring very distinct, from 2 mm. to 4.5 mm. 

 broad; tracheids remarkably large, thick walled, closely covered with 

 from one to three rows of large bordered pits on the radial walls and 

 a few scattered ones on the tangential walls; medullary rays simple, 

 from 2 to 49 cells high, covered on the lateral walls with numerous 

 oblong pores; resin ducts simple, numerous, composed of a chain of 

 thin walled cells. 



" The type of this species was collected by W J McGee of the U. S. 

 Geological Survey, from excavations made for the new reservoir of the 

 water-works extension, Washington, D. C. It had originally a length 

 of nearly forty feet and a diameter of almost two feet. It was somewhat 

 flattened by pressure, the shorter diameter being considerably less than 

 the longer. The trunk was exposed at a depth of about twenty feet 

 below the surface, and must have belonged originally to a tree of large 

 size. To the naked eye the annual rings are very indistinct. The 

 medullary rays, however, are easily observed and are seen to pursue a 

 very tortuous course, due, in part at least, to the dislocation caused 



