THE MARYLAND CYC'ADS. 4»jr) 



It is a small fragment from the side of a largo trunk, convex without 

 and concave within, like a segment of the wall of a cylinder. There are 

 .som(> indications that it may have l)elonged near the base, but this is not 

 certain. The fraclui'c on the lowei' side is irregular, the inner part pro- 

 jecting below the outer; it is also oblitiue on both sides, but unequally so, 

 one side I'ising almost to the line of the upper fractui'e. The latter is 

 nearly horizontal, but lower in the middle. The specimen is well pre- 

 served, thoi'oughly silicified, firm, and moilerately heavy. It is of a light- 

 brown color. The maximum length preserved is 14 cm., but this is on the 

 inside. Of the external surface it is nowhere more than 10 cm. Its 

 greatest dimension is tangential and slightly exceeds 24 cm., Init an arc on 

 the external surface between the same points measures 27 cm., and on tlie 

 internal 20 cm. The radial thickness varies from S cm. to 1 1 cm. (Local- 

 ity: PL LXXX, Xo. 50.) 



PI. LXXXVH, Fig. IV, 6 shows Yeiy well the outer surface of the 

 Ring fi'agment, W. C, B., Xo. 1480. It is a much worn fragment from 

 the side of a large trunk, perhaps near the base, showing the armor and 

 woody zone only. It is moderately silicified, and a fresh fracture shows a 

 somewhat sandy appearance. The color of the outside varies from a light 

 brown to reddish, and at one end black, but this latter is only a stain. The 

 exposed outer surface is 23 cm. in vertical and 27 cm. in circumferential 

 measurement, but there is very little curvature to the latter. The frac- 

 tures wedge in toward the interior so that the corresponding dimensions of 

 the inner surface are 17 cm. vertical and 14 cm. lateral. The thickness is 

 about 10 cm., and the concavity somewhat exceeds the convexity. The 

 thickness was douljtless considerably greater before the surface was 

 eroded. (Locality: PL LXXX, No. 62.) 



PL LXXXVII, Fig. IV, 8 is a view, somewhat obscured by the speci- 

 men standing before it, of the outer surface of the Snowdon fragment, 

 W. C, B., Xo. 3054, lying on its side. It is a compact fragment, of a 

 somewhat circular form, broken out of one side of a large trunk, the frac- 

 tures on all sitles following the direction of the organs of the armor. This is 

 always at a greater or less angle to the nearly flat outer and inner surfaces, 

 but on one side the angle is slight, while on the other it is about 45°, 

 which shows that it must have been near the narrower side or edge of an 

 elliptical trunk, while the opposite side of the fragment represents its 



MON .XLVIII — 05 30 



